If you do so, I would like to point out the following:
If possible, please try to abstract as good as possible "default" version control stuff from the harvest specific one. I believe every version control system has atomic functions such as check-in, check-out, update etc. but the specific command behind will be different.
Why I'm saying this? C::B could really use a nice plugin (or several plugins) for version controls systems. So your implementation (if you do the job) might be a good basis to attach other version controls systems, too. And that would be GREAT!
You might wanna have a look at the C::B SVN plugin from Thomas. It's available from berlios as well, allthough development is ceased at the moment *sigh*.
With regards, Morten.
Ps.: Thomas: You can't clone yourself several times, can't you?! ;-)