Hi Paul,
The IMD pistons rings are coated steel, not the original conventional cast iron, so recommend you get advice from your machinist on honing the bores to suit.
The bedding-in of Cast iron rings in bores honed to a coarse grit ( about 150 grit) is responsible for a fair bit of the sludge buildup in the sludge trap, and contributes to excessive wear of the motor generally. Frequent oil changes help considerably.
Modern motorcycles can do 60,000 miles or more between rebores but our old bikes used to get up to 25-30,000 miles before wear or lost lubrication due to blocked sludge trap required a tear-down and rebuild.
My machinist honed my bores to a 500 grit size, then "plateaued" off the tops of the honing ridges.
Everyone (almost) also recommend a Return-side oil filter and multigrade oils with high Zinc content for maximum life for our Brit bikes.
You can also read up on "Dry" Running-in. Seems very popular on this Forum for cast iron rings. Probably not best for modern rings however.
I will duck now to avoid the stones.
Col