Good advice on pulling the pan.
But I see no reason to hone the cylinders if the same rings go back in. They're already seated, and just because the piston was removed doesn't mean they won't seat back in as before.
The 750 is a pretty easy-going engine so I woudn't get too concerned about big-end bearings - not unless you find a bunch of sludge in the pan. These bikes run at really high oil pressure and the bottom ends are practically bullet proof as long as they've got clean oil. They'll last hundreds and hundreds of thousands of miles. Proof? Last I looked, crankshafts new were about $500, probably more like a grand now. It's hard to give them away - nobody needs em.
The problem with measuring the end gap is removing the ring from the piston and then re-installing. Those things are brittle and it's possible to break at any time. If the bike ran decent - idled ok, didn't smoke, I'd leave them. It's pretty normal for the cast-iron cylinder bikes to get somewhere between 1K miles to 2K miles to a quart. Just to give you an idea.
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