Originally the No. 1 1/2 had the roll-stamped dog on the sides of the frame, a bit of zig-zag border engraving and Damascus barrels --
Ithaca Flues No. 1 1 2, 1912-13.jpg
By July 1915, Ithaca Gun Co. came up with the bold floral engraving for the No. 1 1/2 and also added a choice of barrel material --
Ithaca Flues No. 1 and one half, July 1915.jpg
With The Great War cutting off the supply of barrel materials every catalog showed some changes to the No. 1, No. 1 Special and No. 1 1/2. By 1918 the No. 1 Special was gone and the No. 1 which originally had Twist barrels had steel barrels. Finally by the December 1919 Ithaca Gun Co. catalog the No. 1 and No. 1 1/2 were combined as the new No. 1 --
No. 1 Dec. 1919 color catalogue.jpg
The No. 1 with the bold floral engraving continued into the NID era --
500155 1.jpg
finally being dropped in the 1935-6 time frame.