I just plugged in a quick google search. I am sure their is a speedmaster forum that could be of help as well.
chrono24.com/omega/speedmaster-professional-moonwatch--id23381762.htm#gref
https://sabiwatches.com/product/1983...5-022-long-s-r
https://www.ebay.com/itm/28348284074...UAAOSwPEtc2K5S