Here in New Orleans bike theft is rampant so we have a local Facebook group whose members are attempting to stem the tide (with
some success.) Abandoned frames are often reported to the group and upon noticing that that this one was a Mercian I went and picked it up.
I don't know Mercian models but the serial number seems to indicate a '79 of some sort. It was in pretty bad shape even before being sawn in half (rusty, random low-end drivetrain components and wheels) but with those lugs and forged Campy dropouts it must have been quite a bike once. Mercian will replace top/down tubes at £99 and then there's the repaint but would it be worth it?
It's just about my size, too.