Thanks for moving the repo, that's great. Please feel free to collaboratively maintain the package; that's what collab-maint is for!
A couple years ago I reworked the f2c compiler and library into a single source with an autotools-based build. I have not uploaded it, but I think it's all pretty much good to go. https://github.com/barak/f2c-1.git If you'd have a look, I'd very much appreciate it. Seemed like a big step to replace the current f2c / libf2c with this so I didn't actually push the red button. But I think it would make sense at some point. Especially if upstream is not completely moribund as I'd assumed, but maybe could be convinced to upstream this. Anyway, I'll have a look at the new upstream release, and try to document some of this per your suggestion, in debian/README.source or such. Cheers, --Barak.