@Matthew
Here is the code for the Application Message retry count:
SELECT retried_count
, a1.*
FROM address_label a1
WHERE a1.application_message_id = &MessageID
Also of interest for the remainder of the Application Message data:
SELECT a1.*
, a2.*
FROM application_message a1
, message_queue a2
WHERE a1.queue = a2.queue_id (+)
AND a1.application_message_id = &MessageID
SELECT a1.*
FROM message_body a1
WHERE a1.application_message_id = &MessageID
The code is from the Server Trace tab of the Debug Console which I turned on just before I queried for a single Application Message.