Stihl doesn't have data on the older saws. Here's a reply I received a few months ago:
"I’m sorry to inform you that your STIHL chainsaws were manufactured (Pre-2000), and are too old to be found in STIHLS database. The STIHL Contra 06 was manufactured between 1959-1968, Contra S 06 1964-1968, STIHL 07S 1965-1968, and the 038 Magnum 1985-1997. I hope this helps and please let me know if I can be of any further assistance."
Why don't you post up a few pics of your 038 Mag? Does it have the dual or triple port muffler?