OK. I'll try to get it measured in a competent way. Regardless, it's been liberated of almost 2" of whatever it had when it left the factory and I'd assume that act left little remaining choke. I get now that a drop in is not the best source of truth, but they are not without value in what they tell you are they?

It os all dependant on actual bore size. If the bore is .729" or even close, a drop in gauge will be accurate. But if it is much oversized, it is not.

If your drop in is measuring Cyl on both sides, then the bore is likely oversized.

If only 2" was taken off, you should be getting a light mod measuremrnt. Assuming full chokes on the original 30" length.

Another thing... The letter may not mention choking. Likely just patterning info.

I think they are off the market now, but the best tool investment I ever made was for a Skeets set with two heads that could cover from 28 gauge through 12 gauge. I purchased a cut barreled L.C. Smith Specialty grade in 16 gauge and thought I had won the lottery. Sent it to Dewey Vicknair for inspection and he told me it had cut barrels and no choke left. I purchased the Skeets from Brownells the following day. Its saved me a ton of money since. One has no idea what's been done to a bore until one measures the bore diameter. It can truly be an eye opener.