The WX is still in active demand, about 3-4 years back Dalton's lifted one out through the roof of an office block (converted from a foundry) down the road from my flat at the time, apparently they'd spent a long time tracking it down to rebuild and supply to a customer.On that point, I spoke to a pattern maker recently - I was enquiring about casting a new table stop mechanism - he said they got rid of their LQs because they were only really used as a drill press. Everything else was done on the WX.
He said the lq was limited in its capacity and that its head doesn't rotate.
Anyway, anacdote aside, I suppose the LP/LQ predates the advances which made the router possible, so would have filled that niche for mass manufacture of things like stair strings for a time.
I know Wadkin were active in the production of NC overhead routers and gantry mills for the aerospace sector after the war, but with the exception of the LZ spar miller no documentation seems to be available to identify those machines (at least online), and I've used early 60's vintage overhead pin routers from Wadkin which are about the same working envelope as the LP; which probably explains their removal from the range so early.