Hi Tony,
Welcome to the wonderful world of Blitz Rims. I've had Bridgestones fit on like a glove and no luck what so ever with MRF's. Bought some US tyres that were guaranteed to fit... didn't.
Don't take them to a tyre shop, you"ll just waste yours and their time, been there done that and no one is happy.
Find someone with a large lathe and take 2 ml off the rims. This cleans all the rust pits out and makes the tyres fit. Take care with the edge where the bead fits.
Also hammer wood in behind the rim when in the lathe to stop the ringing or wear 3 pairs of ear plugs
Yes it makes the rims thinner so don't carry 12 tons in the back or jump buses in it.
Some people claim a tapered or flat bead edge makes a difference but that made no difference in my case. Good luck.