I was surfing to find a bridge design of a mandolin banjo, of all things.
In the process I stumbled across a fascinating site that sells antique instruments & parts.
It must be the most basic website I have ever seen, and yet also one of the most fascinating.
http://hopestreet-music-emporium.com/
I did see he has a stock of old vacuum tubes, which may be of interest to forumites:
http://hopestreet-music-emporium.com/vacuum%20tubes.htm