Update....with a strange finding!
The guitar has been cleaned up. The wooden disc "resonator" is dished but is useable until I can make a replacement.
CBJs bridge is great as usual and has given me the action and playabilty that I want.
Now the strange finding (note this has a slotted headstock)....
Set of Martin 80/20 12s at the ready, ball end into the tailpiece, pull string over the nut ready to poke through hole in the machine head - NO HOLE!
That's right- NO HOLE!
These machine heads are three on a strip and seem to be original.
There is no hole in the brass post but a slot / blind hole running at a downwards angle towards the centre of the headstock from halfway along the length of the string post.
A groove is also cut centrally running around the circumference of the brass post.
After nearly two hours of fiddlin' and swearing I finally got it strung up having worked out that the end of the string needs to be poked into the shallow blind hole.
The rest of the string then winds round the poked in bit thus gripping it.
I've never seen or encounterd anything like this in my guitar playing life.
Any ideas? Anyone know what these machine heads are?
Please don't ask for a photo just yet - I'm not going to go through that pain again until I have to.