How easy/difficult would it be to run 6 speed on a hope ss hub (got one spare and don’t want to splash out on a new hub yet!).

Is it just the case of buying a cheap 10sp cassette and splitting it (assume i could drill the rivets out on a deore cassette rather than a fancier carrier mounted one) and then choosing what cogs to run? obviously would need to sort out the limit screws on the mech so it doesn’t overshift!

Sounds about right but you may find it impossible to limit a SRAM mech sufficiently without some top class bodging as IIRC the low screw isn’t long enough and if you put longer screws in the pad isn’t long enough and the screw falls off the end.

Though I’m sure there’ll be someone has made it work.