Neither dealer is giving minimum wall thickness and I'd be very concerned In these guns known for thin barrels and frames that crack.
Flues 20-gauge ad, 1910.jpg
I'd be very concered about the wall thickness on Mikeej99's gun around the forcing cones, as I doubt that light weight 1912 20-gauge left Fall Creek Waterpower Lot #6 with 2 3/4-inch chambers.
The No. 1 1/2 got the bold floral engraving in mid-1915 --
Ithaca Flues No. 1 and one half, July 1915.jpg
By the June 5, 1918, Ithaca catalog the No. 1 1/2 was no longer being offered with Damascus barrels.
No. 1 1-2, June 5, 1918, Pocket Catalog.jpeg
In late 1919/early 1920 Ithaca thinned their line and the floral engraved gun became the New No. 1.
No. 1, 1919-1920 Pocket Catalog.jpeg
Threaded Mode