Good News!!!... well mostly.
The combo switch unit from a 93 Swift hatch is very similar, it uses the same stalks, same housing, and same PCB. However, the swift one has a different set of plugs, no intermittent (a seperate PCB is added onto the back of the sierra unit) and possibly some different wiring/pin outputs.
In my case I was just looking to replace a broken wipe stalk, so I took apart both of the units removed the stalk assembly from the swift (adding a missing contact [swift had one contact, sierra has two]) then put it into the sierra unit. Job done!
If anyone wants pictures I can upload them to show the differences between the two units.
One word of caution if you pull apart one of these combo switches, MAKE SURE THE HAZARD SWITCH DOES NOT MOVE! It has a stupid little spring that sits underneath it, that when let free is an absolute PITA to get back in.