Okay I'll give a quick update: I created MechaHub.com to preserve Lego Mecha models which were being lost on the internet. Gla Gla being one of the best. I own the site and am currently the only person updating it at all.
That said here's what I know. The Japanese in general use fake names when building Lego: Gla Gla is one of them. Nobody seems do know who he really is (or was). I've spoken with at leat 10 Japanese builders and the best I've gotten is "I saw him at a meeting once".
When I emailed Gla Gla almost 2 years ago the (very) rough translation I got back was this:
"How do you do Mr. Bryce Although mailing is splendid, since I am
not familiar with English, the mind to read does not do English mail.
If it is a long sentence, it is still more so. Although it feels
sorry, from the next, I need your help in Japanese. I am not already
GlaGla and will not have the mind in connection with the community of
LEGO from now on, either. Since he plans to assert no right about the
picture before raised to BrickShelf, although you may have you use,
present I cannot think that there is worth of that. If very well,
still use freely. Then, I am sorry."
I'm sorry guys but that's the best I can do. It looks like you have most of the pictures in this thread.
