Brilliant! I know that Technics come with a -8 to +8 pitch slider, so if you know a DJ, or are one, I think you could hack that part analog. I believe the 16 units are in terms of %. I wonder to do a complete analog hack, if you could get a crazy long stylus, bend it at 90 degrees (long enough that it clears the side of the head), then play it with 2 record players at right angles to each other, one spinning, and one amplifying. You would need a player that has a free arm, like a Technics. Kind of madness, but fun to consider.
Not much difference between 78 and 80 rpms, I'd bet the average listener who was familiar with a song wouldn't even notice. 45's played at 33 are very noticeable, but also a sometimes enjoyable novelty. I work with two guys who like playing 45's at 33 rpms, sometimes it's fun other times it drives me nuts. My buddies tape label has a whole album of 45's at 33 Heavy Curtains. You can listen to the tape online, it's fun enough. The wife and I recently inherited a jukebox and I don't know how many 45's (a few hundred maybe?). When I told my work mates about it they both said "bring em in so we can play em at 33.