Are the keycaps on the HP-46 "standard"?

[John Ioannidis]

"The great thing about standards is that there are so many to choose from" -- Andrew S. Tanenbaum



I recently acquired an HP-46 described on *that site* as "parts only". (I have another HP-46 in reasonable condition -- printer makes too much noise -- and although it will probably outlive me, it is good to have spare parts).

Before I start shaving this particular yak... does anyone have mechanical drawings for these keycaps? I intend to 3D print a few, and although I do have calipers, having the actual drawings will be a lot easier.