Oily rag or conservation cup.

[Geoff Kingston]

Chris,
Sounds like an awkward choice, Dave Ralls who has done the work on my cars used a finishing method which does not put any great shine on the leather, not a matt finish but a sort of mid way in between.
He did an S2 Bentley for me where parts of the leather on the front bench seat were just too far gone to retain, the new leather was given this treatment as was the rest of the remaining trim, with use it is surprising how quickly this blends in visually though the new leather is not quite as thick as the original overall the effect is quite pleasing, some of course would rip the whole lot out especially as all the bodywork was done but but that would have been a shame robbing the car of a lotof its character and history.
I have seen also in one of the magazines a vintage car re trimmed in a slightly distressed leather this was very effective and it might be worth asking your trimmers about this. It looked aged not neglected.
Your idea of using the backs would appeal to me as the seat faces are going to get the most wear and time will balance it out.
Geoff.