Cannot implictly convert values

I am having some difficulty with creating a class and passing decimal, date, boolean and even some integer values to the class from my Domain Service in a Visual Studio 2010 C# Silverlight application. There are several articles on this subject on the net but they are currently above my knowledge of C# and WCF and I cannot find a single example that passes anything other than a string or an integer. For the most part I have that working but some of my integer values require a suffix of .Value and some do not. I am not sure why.

The class I am trying to create and use is defined as:

Class to be populated

  public class pmEmployee
    {
        [Key]
        public int id { get; set; }
        [DataMember]
        public string member_num { get; set; }
        public string last_name { get; set; }
        public string first_name { get; set; }
        public string middle_name_or_initial { get; set; }
        public string address1  {get; set; }
        public string address2 { get; set; }
        public string city { get; set; }
        public string state { get; set; }
        public string zip { get; set; }
        public DateTime birth_date { get; set; }
        public DateTime hire_date { get; set; }
        public string home_phone { get; set; }
        public string cell_phone { get; set; }
        public string work_phone_and_extension { get; set; }
        public string work_phone_extension { get; set; }
        public string SSN { get; set; }
        public string clock_num { get; set; }
        public int local_id { get; set; }
        public int site_id { get; set; }        
        public string email_address { get; set; }
        public int member_status_id { get; set; }
        public int member_type_id { get; set; }
        public int member_job_title_id { get; set; }      
        public string Marital  { get; set; }
        public string sex { get; set; }
        public string notes { get; set; }
        public int race_type_id  { get; set; }
        public string urnumber { get; set; }
        public string bad_address_ind { get; set; }
        public int dues_rate_id { get; set; }
        public decimal cope_contribution { get; set; }
        public bool grievance_exists_ind { get; set; }
        public decimal overage_amt {get; set; }
    }


The Domain Service Iqueryable I am hacking away at is:

public IQueryable<pmEmployee> GetEmployee(int EMPID)
        {
            return from emp in ObjectContext.tblEmployees
                   where emp.id == EMPID
                   select new pmEmployee()
                   {
                      id = emp.id,
                       member_num = emp.member_num == null ? null :  emp.member_num,
                       last_name = emp.last_name == null ? null : emp.last_name,
                       first_name = emp.first_name == null ? null : emp.first_name,
                       middle_name_or_initial  = emp.middle_name_or_initial == null ? null : emp.middle_name_or_initial,
                       address1 = emp.address1 == null ? null : emp.address1,
                       address2 = emp.address2 == null ? null : emp.address2,
                       city = emp.city == null ? null : emp.city,
                       state = emp.state == null ? null : emp.state,
                       zip = emp.zip == null ? null : emp.zip,
                       cell_phone = emp.cell_phone == null ? null : emp.cell_phone,
                       local_id = emp.local_id.Value,
                       home_phone = emp.home_phone == null ? null : emp.home_phone,
                       work_phone_and_extension = emp.work_phone_and_extension == null ? null : emp.work_phone_and_extension,
                       work_phone_extension = emp.work_phone_extension  == null ? null : emp.work_phone_extension,
                       SSN = emp.SSN == null ? null :  emp.SSN,
                       clock_num = emp.clock_num == null ? null : emp.clock_num,                      
                       site_id = emp.site_id.Value,
                       email_address = emp.email_address == null ? null : emp.email_address,                      
                       member_status_id = emp.member_status_id.Value,
                       member_type_id = emp.member_type_id.Value,
                     //  member_job_title_id =  emp.member_job_title_id.Value,  
                       Marital = emp.Marital  == null ? null : emp.Marital,
                       sex = emp.sex  == null ? null : emp.sex,
                       notes = emp.notes == null ? null : emp.notes,
                 //Bad      race_type_id  = emp.race_type_id.Value,
                       urnumber = emp.urnumber  == null ? null : emp.urnumber,
                       bad_address_ind = emp.bad_address_ind  == null ? null : emp.bad_address_ind,
                   //    birth_date = (DateTime) emp.birth_date.Value,
                   //   overage_amt = emp.overage_amt
                       
                 //      dues_rate_id = emp.dues_rate_id.Value,
                     
                       
                   };
                   }
                //        overage = double.Parse(emp.overage_amt), CultureInfo.InvariantCulture.NumberFormat)
                //  

I am not sure why some of the integers which are commented out cause problems but when I add them bound to a grid the system goes off to never never land. The date, decimal and booleans. For instance if I hold the mouse over birthdate when it is not commented out it says:

DateTime? tblEmployee.birth_date
No metadata documentation available.


for overage_amt which is a decimal value in the original table I get the message:

Cannot implicitly convert type 'decimal?' to decimal. An explicit conversion exists (are you missing a cast)?

Please don't point me to microsoft articles on WCF I have read them all and do not understand them I am looking for help with my variables.

Thanks,

Larry