Dunk i have a pair of TS substantial guide scope rings that might suit. I measured the internal diametre of 90mm, they are advertised as fitting a 85mm scope. This is the set:
https://www.teleskop-express.de/shop...-to-85-mm.html
I have had them in my cupboard planning to use them to replace my old ZWO rings but have not got them setup on a dovetail bar yet. You would need to mount them on a top rail or bar. Your welcome to use them. If i had known earlier today i could have sent them to Brisbane by plane when my son flew back there this evening. PM me if you want them. I don't want to sell them but happy to lend them to you for no cost, well maybe postage.