OK thanks for that. The rail is a big old hefty thing, a single one, but I will give what you say about a strip down andlooking at all the nuts and bolts a go.At a guess, I would look almost anywhere other than at the linear rail, if it is a real one.
Strip down, find loose bolts, and rebuild. 50% chance.
Cheers
Roger
I'm getting quite excited at the prospect of turning this old router into a better machine...