Retro preamp, pre remote controll era, how best to add a stand alone volume remote


Hi guys I’m keen to add a remote to a fine ol preamp, not wanting to mess with opening up the amp case, but add a remote controll that turns the volume pot - via a rubber band or similar.
I’ve had a quick look through Audiogon, to no avail. I can assemble a kit I imagine, or source the parts separately. Just wondering if someone out there has been down this road and what they used and how well it worked?
I wound probably need to get the parts online and shipping wound be ti the distant land of New Zealand. Your thoughts? And many thanks in advance!
sdj888