Hello Cliff, and welcome to the forum.

With these old guns, the best and most accurate way to determine chokes is via the use of a bore gauge. Since cylinder bore dimensions varied somewhat between manufacturers back then, muzzle plug gauges sometimes used on modern firearms disregard the as-built constriction measurements between beginning and end of the choke tapers on the older guns. Any local gunsmith would have a bore gauge and could measure the constrictions for you, or you could purchase a reasonably priced Skeets Bore Gauge or the like so that you could determine for yourself the chokes on any shotgun you might be interested in going forward.

Also, you might want to re-check the barrel length on your Ideal grade. If its not a single barrel trap gun, then it'll be the first I've heard of with longer than 32" barrels.