Gentlemen,

Thank you for your advice and clarifications. Here is what I did:

I bought the Manson Wall Thickness Gauge from Brownells for $100.00.

I bought the skeets 12/16 dial bore diameter gauge from Brownells for $85.00.

I bought the choke / chamber gauge from Galazan for $45.00.

So for $230 I can now understand the state of a 12 or 16 bore gun. For another $85 I could be all set for 20/28 to round out the list.

I'm just thankful I can decide whether to buy or not buy, to hone or not hone.

Thanks for your kind responses to my questions.