Yes, I was a bit concerned about the endpin socket requiring a larger hole, having looked at one now. The point of not wanting to make mods to the guitar itself is so that the pickup can be removed leaving the guitar in its virgin acoustic state. That's one reason I didn't consider fitting a pickup that required a preamp or equaliser unit (or whatever those things are called with the sliding controls) and making large holes in the side of the guitar body - once fitted there would be no going back.

Which brings me to a second question: having resolved the question of the pickup itself, the next stage would be to have some sort of external control that I could plug the pickup into, that would allow me to adjust the volume at my end. I've seen people using little boxes they plug the guitar into, mounted on the mic stand, with built in tuners - they look like a good idea to me. Any recommendations for makes/models to look at?

Thanks again for all the helpful advice - Mudcat comes up trumps again!