jms_bytes message type - trying to decode message body...

i'm receiving a message from MQ - it originated on a mainframe.  the message as it reads in my onMessage is this:

JMS Message class: jms_bytes
  JMSType:         null
  JMSDeliveryMode: 2
  JMSExpiration:   0
  JMSPriority:     0
  JMSMessageID:    ID:c3e2d840d4d8f1d74040404040404040bcd3a02452f62407
  JMSTimestamp:    1112884972650
  JMSCorrelationID:null
  JMSDestination:  null
  JMSReplyTo:      null
  JMSRedelivered:  false
  JMSXDeliveryCount:1
  JMS_IBM_MsgType:8
  JMSXAppID:JDONTHF                    
  JMS_IBM_Format:        
  JMS_IBM_Encoding:785
  JMS_IBM_PutApplType:2
  JMS_IBM_Character_Set:37
  JMSXUserID:jdon        
  JMS_IBM_PutTime:14425265
  JMS_IBM_PutDate:20050407
Integer encoding: 1, Floating point encoding 768
e3c1d3c8d6d3c45c5c5c5c5c5c5c5c5cf0f0f2f0f0f0f1f44c849485a2a28187856ef0f1f2f14c84
888581846e4c849683a3a89785c9846e88969384899587408685854c61849683a3a89785c9846e4c
a296a4998385c9846e9481899586998194854c61a296a4998385c9846e4c8696999481a3c9846e86
89a785846093859587a38840a385a7a34c618696999481a3c9846e4c6184888581846ef0f0f9f44c
848496834085a7a38599958193c49683c9847e7fc8c6f0f0f0f7f1c2c2f5f2f0f0f5f0f6f1f27f40
85a7a38599958193e58599a2899695c9847e7f868999a2a3409596a38983857f6e4c5abac3c4c1e3
c1ba40404040404040f0f0f2f4c4c8c6f0f0f0f7f1c2c2f5f2f0f0f5f0f6f1f2e8f0f3f0f5c8e7e8
e940c1c4e5c5d9e3c9e2c9d5c7404040404040404040404040404040404040404040f1f2f340e64b
40f1f8e3c840e2e3d9c5c5e3404040404040404040404040d5c5e640e8d6d9d26b40d5e840f1f0f0
f0f94040404040404040404040404040404040404040404040404040404040404040404040404040
...

I've tried to decode the darn thing w/ASCII, UTF8, Unicode, IBM437...

               BytesMessage tmpMsg = (BytesMessage)message
               int writeIndex = 0;
               byte[] buffer = new byte[2048];
               byte[] body = new byte[0];

           while (true)
                    {
                        int numBytesRead = tmpMsg.readBytes(buffer);
                        if (numBytesRead == -1)
                        {
                            break;
                        }

                        byte[] tmp = new byte[body.length + numBytesRead];
                        System.arraycopy(body,0,tmp,0,body.length);
                        System.arraycopy(buffer,0,tmp,body.length,numBytesRead);
                        body = tmp;
                    } //end while    

               String msgBody = new String(body, "<encoding>");

no dice.  i get a garbage string every time.  can anyone shed some light?  thanks!