I don't know that there is a 'right' answer to your question/s, but I do know what I would do if I were in your shoes. Seems to me that you have two problems, one is replicating a working solution and the other is updating 'parts' as they change. To handle the first I would go ahead with your list of '.gz' files, except I would use it to power a perl script to automate the install procedure. It would do for each .gz the usual make this that and the other thing---all in the correct location probably from a tempory directory, then cleaning up afterwards. There may be some 'hand' work left afterwards, but if it is invariant, then script it back into your build process. Generalize this so that you can point at whatever box you need to and you should have a leg up on the first problem. The second would require monitoring the CPAN published list looking for hits---from which you could do the appropiate thing, dl, etc. I'd also do all of this with an eye towards doing as little as possible in order to get the job done, as it seems to me that in your case, 'least change' is probably 'best change'...

--hsm

"Never try to teach a pig to sing...it wastes your time and it annoys the pig."