I'm not an Ithaca collector, but maybe I'll do as I have an answer. Polished laminated iron/steel usually does not show the pattern of material difference. Actually, it may take a good deal of effort to bring out the pattern, depending on the exact alloys. Blued/blacked pattern steel may not show the pattern except in very strong light and with careful inspection.

"False damascus" is mostly a red herring. It was done to cover up seam welded sheet steel barrels of very cheap guns. Ithacas, even the cheapest grades, were a long cut above that level.