HP48S/G Manufacturing / Variant History - Comments?

[TomC]

All:
As you may know, 'megarat' has done a fine job of maintaining a list of HP48 (S and G series) machines and the manufacturing timing, detailing OS version variation:

http://www.hpmuseum.org/cgi-sys/cgiwrap/...i?read=991
(article 991 in the Articles page here at hpmusuem.org).

I am curious about timing of a couple other variations in these machines:
1. Change to improved, 'Black' LCD.
2. Change to non-double-shot keys.

Both of these changes happened in the latter days of the 48G series. I believe both changes happened around/after the mfg move to Indonesia.

A couple notes/questions:
1. I have noticed that later 'ID' era 48 non-black LCD, while not black are certainly of higher quality than earlier LCDs.
2. How does one confidently assess whether the keys are double-shot? (non-damaging of course!)?

Comments? It would be interesting to add more resolution to the historical detail of this machine.

TomC