Wow this thread's really taken off in my absence..
The original engine number in the owners manual is 10YJUH.
The engine was replaced in 1999 with a mini K engine (from the same era), prefix 10YCTAH.
I assume this means the car originally had a 'magic wand' shift but was replaced with remote shift in 1999.
As the story goes, the owners elderly mother drove this car around Stawell when she was in her late 90's. Her family wanted her to give up her license as she was too old to be driving, but she refused to give up driving her mini. So they thought the best they could do was take it into Link Automotive and get them to do "whatever it takes to make this car as safe as possible". This is when they replaced the seats with the high-backed ones, and replaced the engine. The owners didn't think there was anything wrong with the old engine..
I'd like to know what happened to the original front seats. Apparently they were in good nick. The back seats are red vinyl, but sort if with a fine texture pattern to it, kind of like an old table cloth

. They are similar fabric to what I've seen in a mini 850.
On a side note, I'll have to confirm but I think the engine has the temp sender in it (as it's from a mini K) just not connected to anything. I assume it'd be a relatively simple job to wire in a temp gauge.? I'd like to get a little, simple 'smiths' gauge or something that won't detract from the car, and mount it below the dash shelf.