Anyone got historical versions of code - version 1.5 to be exact

Real long shot here!
I have taken on a client that is running a very old version of Egg (1.5).
I would like to upgrade them to the latest version, but obviously this is looking like a bit of a large task.
I think the original developer altered lots of core code, but I don’t know for sure.
To make this even possible I’d need to diff my current code with a vanilla 1.5 source tree.
Elggs GitHub repos only go back as far as tags.
Is there any chance someone still has a 1.5 version of the code somewhere?
Thanks in advance