I think there is a lot to be hopeful about. First of all, if you can find a framebuilder who is skilled with silver (not all of them are, it's very runny), and then do it in a way that protects the nearby chrome, perhaps with flux, as someone else has suggested.
If some nearby chrome is slightly damaged, this is not a problem. I have had very good success restoring damaged pea-sized bits of chrome with a brush chroming set and the right grits of sandpaper (600, 1000, 1500, 2000) and nevr- dull (or its sister, simichrome). The restoration is completely undetectable, except under bright flourescent lights, and only for someone who knows what they are looking for.
This might be the time to invest in a $31 brush chroming set from http://www.caswellplating.com. There are a myriad of things to use it on in any CR garage. And, don't forget that nobody sells high-grades of sandpaper cheaper than caswell plating.com, at just 10-20c for each large sheet.
- Don Gillies
San Diego, CA, USA