Go on eBay & look up your sewing machine exactly the way you wrote it here.
I I have a singer machine model 111w151 I would like to know how much it is worth it is attach to a table?
With any collectible vintage item, condition is everything. I've seen them sell for $100 and I've seen them sell for $1000. I know that's broad but without a picture I can't suggest a more accurate appraisal. You might try a seamstress, many people collect vintage tools of the trade, they might have a better idea. You could also have it appraised at a local antique shop.
