I've had a few days of busted knuckles and I've made some progress..
The old battery had been a bit weak in starting recently, so I had it checked out at the local battery shop. It was down to 220 CCA (Cold cranking amps) from the original 260CCA. It had gone flat a few times and is on the small side. I decided to buy a nice big one that'll fill up the battery box. The new one is 560CCA, so more than double the power of the old one.

I also bought an extra ground cable and installed a battery disconnect switch to easily isolate the battery when it's parked.

I've also been working on the under bonnet heater. It needed to be connected through the firewall, to get hot air to the passengers and to the windscreen. This turned out to be a really big job:
The oil pressure and temp gauges had to be disconnected
Drain the coolant
Replace the thermostat
Remove the dash panels
Modify the vents
Remove distributor
Relocate the horn
Etc
These are late plastic Clubman dash vents. They didn't end up fitting in the factory orientation as on a Clubman they point inwards and go through holes in the centre of the dash. On my car they need to go through holes on the outside of the dash

I cut the RHS vent short and swapped them from side to side.

RHS vent is now installed

It's all hidden behind the stock dash which I'm really happy with. The LHS is still to be finished


The fresh air intake hose is installed in the engine bay. I've got an idea of how to connect the air to inside..

I gave the engine a quick start to make sure it was all working OK and it blew out the oil pressure line on the block. I ended up having to remove the distributor to fix up the connection.

I'm still to finish the LHS vent, install the hotter thermostat (82 instead of 74) and fill it up with coolant. I've also been messing around with getting the horn working on a new/old steering wheel I picked up at a swap meet..