Going to take a wild stab at this and say...if you were putting them into a left hand drive car it probably would work as the bulkhead configuration might allow it due to cable lengths etc.

I'd also note that alot of parts are LHD specific, I bet search for speedo cables would give you a clue.

Personally I'd hold out for a set of (but they aint cheap anymore) RHD clocks

*Just looked on GGR and they do list LHD & RHD cables separately