I just got a 1939 S/42...some questions about parts

[buymore]

1939 S/42 5X28 It is all matching except magazine 7039 (but I was told by several people it is period correct...alum. bottom...same eagel 63 inspect. marks as gun.) I bought it missing the locking bolt and sideplate and the left grip panel has a broken piece up by the mag release....shame. they're matching grips! My question is mostly about the locking bolt......I need to know does this gun need a "28" marked locking bolt or is it blank? I saw a seller selling a blank one that had "s/42" on the top of it. I already ordered some parts just to get it back together ("25" locking bolt and repro side plate) so I can shoot it. I want to work on correct parts now. I have less than $700 total in it with the parts, but It's an almost matching shooter that doesn't have a lot of internal wear. I may not have done a stellar buy, but I am happy so far.