What is the new name for part 6099p45.DAT? Also, how do I look up this information myself for when I run into this problem again? Thanks.
Nothing has ever been released to the official library as 6099p45.dat, so this is either an unofficial mock-up or it got renumbered before being submitted to the Parts Tracker.
In theory, a URL like
http://www.ldraw.org/cgi-bin/tracker/act...099p45.dat should find any activity (including renames) for that file back to the birth of the Parts Tracker events log (15-Oct-2001).
Failing that, the only recourse is a visual comparison between what you have and what patterns are available for that part in the official library.
... and we shouldn't submit Thomas Burger's parts without his permission - which has been impossible to get as all known email addresses fail.