Here 'tis
7.62 source code
The code is a hybrid between C and C++, but if you know either of those it should be fairly simple to understand.
And this was not leaked, and it was a conscious decision of Aperion to release it, they knew it would give the game a longer shelf life. It's understandable, at least when they were still in business, that they wanted to protect their SPM and weapon system.