To be fair it's actually not too difficult to do, just you need to make sure you have plenty of time set aside to do it (try a night when the missus has gone out!). As long as you're not pressured, and constantly clock watching, you'll find it more akin to a very challenging Les Paul re-wire, and the smug sense of self-satisfaction once you're done is totally worth it.
There is only one drawback...............
I've now re-wired another two 335's for friends, as they didn't want to do it themselves! One of them did give me a rather nice bottle of Dalwhinnie mind you for the effort, so it wasn't all bad! :D