Another slight twist and a shedload of questions...
I had a second pair of 1300 cylinder heads in the garage at my Mum's and I took a look at those tonight, stripping the valves out and cleaning up the combustion chambers to check for cracks. The valve seats are also a hell of a lot better than the 1600 heads I split down previously. They are crack free, so getting a pair fly cut now seems a decent option. The valve sizes were 35mm (must have been 35.5 and I mis-measured) and 32mm. These are the two heads, let me know if anyone spots anything alarming!
Now to the pistons... the set of 4 that came off of the 1600 engine have dished pistons. All the pistons have burnt oil marks either side around the gudgeon pins and are covered in crud on the head of the piston, but none have nay major scoring to the pistons or barrels. Any main damage/marks are a big rust streak down one of the barrels.
The piston I took a close look at looks like it will clean up alright and this is one of the other barrels that I did wipe out.
I also measured one of the piston and barrels (I didn't have time to do all 4) with a digital caliper and the ring gaps with a feeler gauge (I measured the gap between the top of the ring and the piston, not the gap between the two ring ends when compressed). These are the measurements:
Top of piston - 85.4mm
Base of piston - 85.8mm
Top ring gap - between 0.25 and 0.30mm
Middle ring - 0.05mm
Bottom ring - 0.10mm
Top of barrel - 85.9mm
Base of barrel - 85.9mm
Do these sound usable if I cleaned them up and out a new set of rings on them? If they do, am I far better off just getting the heads flycut for 1600 and cleaning up these pistons than buying a new top-end rebuild kit with non-German parts?