None of 'em look like "major" contributers of code to me, but my connections to LyX go back only to the start of the millenium.
Four of the names I recognise and my old brain kind of associates them with significant contributions... You might want to focus the search for those 4 in particular:
Robert van der Kamp
<robnet () wxs ! nl>
Miyata Shigeru
<miyata () kusm ! kyoto-u ! ac ! jp>
Mate Wierdl
<mw () wierdlmpc ! msci ! memphis ! edu>
Bernhard Iselborn
<biselbor () rhrk ! uni-kl ! de>
Regards, Asger
