Oooh, a '43! Not so nearly nailed down as either '44s and later, nor as "undefined" as '42s. If late '43 I should think it ought to have most of the "regular" receiver markings.

Stock parts are too easily replaced to be sure of anything there, so don't sweat it unless it looks "improved". No number is fine esp. if no S51 underneath, but then it should have other "later" rifle indicators.

HOPEFULLY, if it's got no mid-swivel, there will be NO rifle S/N on the scope bracket. If swivel, then a number's fine.

If there's no numbers on either the wrist or bracket, well, I shouldn't worry at this point if the price is reasonable enough. Just make sure the appropriate markings are on the receiver proper .

Yes?