I wouldn't bother too much about compound specs, they vary from batch to batch on the same model of tyre.
The workers from the old Olympic factory used to get their staff discount at Beaurepairs, Chermside. They would go to the tyre racks, choosing their tyres according to the batch numbers, they knew which ones had a generous dose of carbon black .
I used to buy 11Rx22.5, second hand, Japanese imports, for use on trailers and dollies. The only difference was the ply rating, 14 for the imports against 16 for Australian supplied. I never had a problem with them, unlike the recaps I used prior.

