well spotted dm, its a standard 1970 model. has a few weird little bits i'm trying to work out like the heater and radio. the radio is an AM pos and the heater is no longer in action but there is a weird little box which i'm going to look further into which is bolted to the little shelf under the glovebox. it was deregistered when sold to me but i retained the original plates and will re register it with them, and the a10 with a gutfull of stopsmoke

Well I can't help with the 'weird little box' thing, but perhaps I can help with the heater.
The coolant flow control valve is built right into the heater core itself & is a cone shaped piece which is hollow & has a single hole on the side. It sits into a tapered hole & as you rotate it with the knob, this hole lines up with another in the heater core & controls the flow of coolant, & thereby regulating the temperarure.
This thing siezes. If it is stuck, DO NOT FORCE IT. If you do you can
Break the plactic knob
Break off the little brass screw that holds the knob to the shaft.
Break off the shaft, & none of this is good.

At worst, you may need to actually remove the heater & dismantle it. This is not a hard job, but just a pain. It may even be necessary to talk to a radiator man about loosening this valve & removing it, as just heating it may melt the solder that holds everything together. There is an O ring involved to seal it, but no problem there. Once it's out, clean it with steel wool & lubricate it with some of that white lube that you use on housedold tap threads.[from plumbing supplies or hardware stores]

Make sure that the core is serviceable, re-assemble with a new O ring & install. Once it is working as it should it will be all nice & toasty inside, even on the coldest days.

B10, The car you always wanted.