I'm not a clockwork fan.
I just have one, use them as a lever extender.
Pretty common on Oranges at the time, you see old bike crop up with them. (not so much the ram rods.).
Just clockworks are bikes people dump at the tip since they're old, 'cheap' at the time and a bit naff.
But they were only around for a few years and most bikes will have been dumped way before now.
Frame is manufactured in December '92, so I guess a '93 bike.
The serial starts with an A, so does that mean it was made by A-Pro? I've seen Lynskey and Sandvick mentioned as manufacturer's before.
The seat tube comes up as 26.6mm on my calipers, which also measures a 26.8mm controltech post as 26.5mm; so I'm probably going with that.
I'd seen 27.0 and 27.2mm mentioned before.
I tried a 27.2mm post and there was no chance of it fitting.