Had a bit of a look over last night. Spark Plug terminal is gone and replaced with a poorly secured ring terminal - have ordered a proper terminal and boot for this.
Engine turns freely but can't feel any compression, I'm guessing/hoping they have a decompressor setup, can hear it 'breathing' when pulling it over slowly so assume this is correct but glad of anyone who knows this era Honda better than me to comment.
Belts aren't in great condition but this is to be expected, the main clutch for reel drive is very stiff to operate but does work. The ground clutch seems to engage/disengage from turning the main shaft over by hand.
Reel is binding a bit, presumably due to rust, might try and open up the clearance to the bedknife a little just for getting it up and running before taking in for a grind.
The front roller appears to have lost a pivot bolt, doesn't appear to be anything broken so this should be an easy fix.
It's nice to look over a machine from when things were built to last, don't think I've found a bearing yet that doesn't have a grease nipple.
If the engine is good, hopefully shouldn't need much to get it running again.