FWIW - silver-bearing solder is available at Radio Shack. You might want to
try there rather than purchase a larger quantity as it is normally sold
through welding supply sources.

I ordered a 1 lb roll of Harris Staybright from a local welding supply.
I don't remember if it was 20 or 40 bucks. I compared the price to MMC
catalog and the price per pound was about the same.

I also ordered 1 oz of true silver solder 56% silver (melt at 1200) for
about 20 bucks. A good mapp gas torch will work on small parts. I was also
surprised to fine that 1 oz of thin silver solder is pretty long, over
20 ft.

The silver-soldered joint held up with no problems taking fairly
light cuts. The joint appeared to be nearly as strong as the native brass.

Did you use a hard silver solder or staybright?
Staybrite is about 95% tin and 5% silver. It would surprise me
to hear that stay bright is that strong.