thinking of a route from accrington over moleside and through rossendale to irwell vale up to cragg quarry and then down into lee quarry. from there up the pennine bridleway to clowbridge reservoir then up to weather station and down the fairy steps……? does anyone in the know think this is doable?

anyone? just wondering if my thinking is correct.

Yes it is.
I take it you’re tinking of Kings Highway then round the back of the Ski slope?
After you drop into Rossendale you can head straight up the road to Townsend Fold and you keep going past the clay pigeon quarry and out onto the top of Gin Croft Lane at Cowpe Lowe. From there follow Rooley Moor road until you can join the Cragg Quarry track and put in a loop of that. If you then carry on down Rooley Moor towards Rochdale you will hit the trail to Lee which isn’t open yet, but I’m sure will be when you come to ride it.
From Lee I wouldn’t o back to the MTL, I would head up to Sharneyford on the back track, then Overto Thieveley Pike and Deerplay Moor, joining the MTL there. A short stretch of that will take you onto the bridleway down to Clowbridge and back from there as you describe.
Looks a top route and will be a big day out!