Thanks drh.
I put a bid on
http://cgi.ebay.com/ws/eBayISAPI.dll...m=330223873934 but am already outbid. I wonder if it would work (do earlier/later 400 remotes work interchangeably?). At least to check out the receiver circuitry, until a correct remote can be found...
A photo of an early one:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=320215194760
Anyone have a photo of the 1958 "piano key" one? Thanks.