The weight of the barrels at proof will be stamped on the underside in grams, which should help you.

In looking at print ads, lifted from Shooters Bibles on eBay, I found one from 1969 showing a 20 gauge Brescia with 25 inch barrels. Other years show 26 inch barrels.
Another lesson to not say " they never made that."

Last edited by Saskbooknut; 02/23/21 04:03 PM.