OK, here is what I found. I am digging through Dave Heckel's "The Stanley "Forty Five" Combination Plane" published in 2002, I got it in 2006, so new information may have come out since then, but this is what was known back then. I don't plan to dig into the different types, you'll have to know that, as I can't find a live one right now, the 3 that were out there are dead and / or truncated to uselessness.
Anyway, the book has B & W postage stamp sized photos of the screwdrivers, and about 2 pages of items to check for each type, so a bit more detailed than most studies I've seen for other planes.
Types 1 - 3, no screwdriver listed, 1884 - 1888
Type 4, 1890-1892
Type 5, 1893-1894,
Type 6, 1895 (No text, just the pic)
All use the same image, a straight bladed, with this text in 4 & 5 "Screwdriver supplied with plane is stained brown and has a straight flat blade or a blade with two scallops cut into the edges of the flat blade"
Basically looks like the bottom two in this picture, without and with scallop look (updated image now included.) Tho the book does not give a length, mine are 4-5/8" long, and a few tool mongers have shared that length in their ads. The center one may be an anomaly, without the little ring at the top of the taper. The books show the ring, but the tool mongers often don't.
Type 7a, 1895 Major Change, Unique prototype - No Pic or text
Type 7b, 1895-1906 Major Change (not getting into early middle and late)
Type 8 , 1907-1908
Type 9, 1908-1909 Major Change
Type 10, 1909
Type 11 1910- 1914
Same text "Screwdriver supplied with plane is stained brown and has a straight flat blade or a blade with two scallops cut into the edges of the flat blade", and two images, both straight and scalloped.
Type 12, 1915-1920 Major Change
Type 13, 1921
Similar text, "Screwdriver supplied with the plane has a
painted black handle, and has a straight flat blade, or with two scallops cut into the edges of the flat blade"
This one looks more like the top one in the above picture.
Type 14, 1922
Major change in the screwdriver world, "Screwdriver supplied with the plane is painted black handle, and has a
round shaft blade, 4-1/4" long and is unmarked."
None of mine look like the image in the book, but the pix below are close. Not the top one has a longer "head"
Type 15, 1923-1935
"Screwdriver supplied with the plane is painted black handle, and has a round shaft blade, 4-1/4" long and is
marked MADE IN U.S.A.."
Type 16, 1936-1948
Type 17, 1948-1960
"Screwdriver supplied with the plane is
maple with a blonde shellac finish, and has a round shaft blade, 4-1/4" long and is
marked MADE IN U.S.A.." This handle almost looks square, but similar ratio to the 14 & 15, but without the long head shape.
These pix are typical for all following, tho the top one seems to have the longer head shape
Type 18, 1961 - 1962
supposedly the same as 17, but no screwdriver photo or text
Type 19 Aluminum 1915-1924
"Screwdriver supplied with plane is painted black, and has a
round handle and a flat straight blade"
Type 19A Aluminum 1924 - 1934
"Screwdriver supplied with the plane is painted black, and has a
round handle, and has a round shaft blade, 4-1/4" long."
Type 20 Canadian 1922 - 1960 (Types 14-17 in US)
"Early models of this type have a screwdriver supplied with plane that has a black painted finish, and has a round shaft blade, 4 1/4" long and is marked MADE IN CAN."
"Late models of this type have a screwdriver supplied with plane that is maple with a blonde shellac finish, and has a round shaft blade, 4 1/4" long and is marked MADE IN CAN."
Edited: updated picture, changed text to match, fixed typos
