Thanks for the reply. You raise an interesting side issue:

I think your "always-handled-like-a-sacred-relic 24" Veritas steel
straightedge"
is no longer accurate to 0.001" tolerance over its length, unless
you've also kept it in a supported box and you were careful about
temperatures when you used it.

I've always stored it by hanging it on a peg through the hole (i.e., it
hangs straight down) in a tool cabinet in my climate-controlled shop.
It's stored in such a fashion that nothing can bump into it, etc., and
every time it comes out, it gets a quick wipe of Boshield before it
goes back on the peg. From what I've been told, that should be OK.

Still, I know it doesn't take much to screw up a precision
straightedge, and although when I received it it was packed pretty
carefully, there's no way to know whether it was dropped, etc., in
shipping.

Ergo, the question: is there an easy / inexpensive way (or place to go)
to check whether such a reference is still accurate?

LKB