There are several other "unofficial" places that you will invariably
find the serial number of the Steinway you are needing, Sam. I don't
know why I forgot about this the first time. Guess I was just thinking
about official company stamps and things.
That will be either written by hand on the action tray, or on one of
the (usually) first 3 hammer shanks, or the first bass whippen, or the
first bass key side. You may also find it "rarely" on the top of the
key bed, either under the key block or wherever, but you have to
specifically look for it.
Often though, you will find initials and a date of the action
regulator, like RAR, 3-29. That means, the action was regulated in
March, 1929, so it would have received its serial number for that year.
That would probably be a number sometime after 265000. Steinway ceased
production of pianos during the depression, anyway, until 1942.
Regarding Bob Taylor's comments about "late model" instruments not
having the "Dance mode," and etc. I restored a Steinway model "O"
having a serial number of 228817, placing it around 1924. It was
originally owned by the owner of Jenkins Music Co, so has always been
in the Kansas City area, apparently. This instrument doesn't have Dance
on the lever either. It only had Normal and Soft. Nor does it have any
of the other hand levers required to simulate expression. You could see
the holes originally drilled for the levers and bushing blocks
required, but could tell that they had never been installed by the
factory, and the expression box wasn't equipped for them either.
The other interesting thing about it is the fact that it's a model "O."
Steinway ceased production of the model "O" in 1923, yet it carries a
1924 serial number. There's an example of a "carry-over" of the serial
numbers back in the middle 20's, too.
I think the moral of the story is this: Whenever we think we've got the
answers to what these companies did and didn't do, we will invariably
discover sooner or later that we were half-right. There seems to always
be those exceptions to the rule. My policy about their policies is to
always be surprised, because you never know what you are likely to turn