You planning on dragging 'em down Hammer?!
Try Mick Turner at Reefers & Wreckers near Clitheroe (about 17 miles from Settle). He sometimes has S/H ones from the PADI school. 01254 825555.
Also may be worth a chat with Mark Hooson in the NS.
Isn't there a pair owned by the Section which are available for booking out? (But I can't remember what the arrangements are for this; it may be you have to be qualified.)