I think pre-WWI, but after 1890 (a shot in the dark, and I actually would enjoy the experts' correction if it's forthcoming.)
For what it's worth, I think your best investment is a microfibre cleaning cloth. And since nobody brought it up, I'd hedge on your asking (not cheap, but poor!) but if it winds up a fair bargain (hint: a bad application of magical violin fluid would significantly lower my inclination to offer for it in the first place) I think I'd enjoy playing it as it comes, no extra "how 'bout I throw in a..."[whatever] necessary. Unless you have a new chinrest that you haven't tried out yet. ;-D
@AlCramer Out of curiosity, is your Maggini patterned more after the actual known instruments, or are you calling it that because it may have double purfling lines and is labeled such? You will see it come up time and again if you stick around. But figure out how important is the distinction, and after awhile one of the Meistergeigenbauern will join you for a liter of... well, whatever musicians drink these days. Leftover dishwashing water, from the tales I've heard