Are these special carbon inserts to enable a 2 bolt cleat (and would they take any 2 bolter, like a Time Atac cleat for example?). Or can they be swapped for a road type cleat? Or would you need to replace the carbon insert?
Yes, these shoes used different inserts depending on the pedal system. There would have been Look and Time inserts, in carbon or plastic. I'm not familiar with the Time Atac system, but from Googling it looks like it would work. From memory the carbon plate just had the twin slots, with the cleats bolting into the plate supplied with the SPDs.
What's the Velcro like on them? Is it still the original?
Still original, and in good shape.
If you like, I can get more photos later.