How to keep using package after dev removed it from repo


A few days ago one of my packages gave me an error that would require its re-installation, but I then realized that it's no longer available on GitHub. Can't get the master zip anywhere else.

Thankfully I had the package on another machine so could transfer the library. I simply copied it over as I have the same version of R on both computers.

I tried to build a binary package so I could install it on a packrat project but couldn't do it. I got an error 'dll not found' and a warning 'S3 method declared but not found'. So I gave up.

I've then created a project and installed all the dependencies and took a snapshot. I load the package I can't build from the external library with extlib().
Everything works fine at the moment.

A few questions though.
-As long as I have the snapshot and the same R version I should be able to use the package indefinitely right?
-To transfer it to another computer, what do I need to take into consideration? R version? OS architecture?

Any help would be immensily appreciated.