Welcome..!

> ... I was apprentice to a harpsichord
> builder, starting
> in '70, who recreated (as much as possible) the building tradition of
> the 18th Century, materials, processes, structure, even
> decoration....

I envy you. Although I don't even play any keyboard instruments I've been
wanting to build a harpsichord since reading Zuckermann's book a couple
decades ago.

> ... an old #3 bench plane that had been bequethed to me
> by a retired carpenter friend...
> Anyone know what this might be?

Vaughn & Bushnell #903 perhaps???

Your description sure sounds like a V&B smoother I have at home awaiting a
tune up (though mine has a logo & model number on the lever cap.) Its frog
looks like what you described (as best I can remember right now,) it's as
wide as a stanley #3 but slightly longer - as long as a #4. Mine's got "flat
sides" that look like a bedrock's.

AFAIK neither the user nor collector communities have any info on V&B
products on the web. Last time I looked, all I could find was some gossip
along the lines of "quality control is all over the place on V&B planes",
nothing more. No one on the porch admitted to ever using one when I asked.
Got any pictures of your #3??

Regards,
Chris O.