Just a update on the hub re line, found this brake disc (NDB776), has 23mm ID and plenty of meat on the out side, would leave quite a thin insert, but think it would be ok. Quite a lot of machining, but half the price of the liner, only £35 a pair,so this might be a new option. Will update when I figure out which way I go with this.
Westwood Cylinder Liners uk do a liner, WCL41BFL , Bore 124, Dia 129.96, length 259.16, about £85 all in. I have machined my hubs 127mm rear, 128mm front , going to give this liner a try, will update if successful.