Looks like an honest 1900. Not prettied up or messed with.
Based on my experience with my 1900AE, I would recommend a detail strip to check things out. Things that went wrong on mine: firing pin spring guide was broken (not serialized); one mainspring leaf broken (not serialized); crud buildup under safety lever allowed lever to flop around (dangerous; pin should be removed, lever and cavity cleaned out).
Grip chip can be repaired, Jim Solomon is really good at that. I
think he could repair it without over-restoring the grip.
How's the bore look??? Mine is very frosty.