Later LAC catalogs state the DS was available only with steel barrels, no cocking indicators, straight rib extension & un-capped half pistol grip stock. There was also no escutcheon in the forend. As noted several are known to exist which have all features of the H, including the twist barrels, except the wood.I feel that several possibilities exist for these.
1; some may be early experimental guns in development of the grade
2; some may well be Ithaca built using up parts. There is a known 1914 Ithaca catalog which had the DS grade x'd out, so apparently they had run out of DS frames. They may well have assembled some guns with H frames & marked & sold them as DS's.
3; LAC themselves may at times have had orders for DS guns but were short of Frames, barrels etc & assembled some using H parts with DS wood & so marked & sold.

I will note I have an Ithaca assembled 12 gauge H grade, twist barreled, marked as H, which has DS wood. It is an extractor gun fitted with an Infallible SST. SN's on barrel & frame are 4 digits apart, which are incidentally unless recently superseded the highest numbers listed in the LACA SN data base. It may well have been assembled like a Johnny Cash Cadillac. Barrels are 28" & it weighs 6 1/2 lb & is not on the XX frame.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra