A collection of all the Masterench variations would take quite a bit of wall space. Below is a list of the variations that have been sold on Wrenching News Auctions (three are probably more). Beside the smooth or serrated jaws and type of opening in the end variations there are several marking variations. The major ones are:
HELLER BROTHERS CO - NEWARK, NJ - PATENTED 4-14-25 - 7-5-27
HELLER - MADE IN USA - PATENTED
LYNCHMEAD MFG. CO. TURLOCK, CAL NOV 21, 1921 - FEB 25, 1921 and PATS. PENDING
6" with smooth jaws and round hole.
6" with smooth jaws and square opening.
6" with serrated jaws and square opening.
6" with serrated jaws and hex opening.
6" with serrated jaws and 12 point opening.
8" with smooth jaws and round hole.
8" with smooth jaws and square opening.
8" with serrated jaws and round hole.
8" with serrated jaws and square opening.
8" with serrated jaws and hex openig.
10" with smooth jaws and square hole
10" with serrated jaws and round hole.
10" with serrated jaws and square hole.
10" with serrated jaws and 12 point opening.
14" with smooth jaws and round hole.
14" with smooth jaws and square hole.
14" with serrated jaws and square hole.
18" smooth jaws and round hole (submitted by BRwrench)
18" serrated jaws and round hole
18" serrated jaws and square hole
Sizes listed are manufacturer's nominal sizes. actual lengths are longer.
I have managed to acquire all but three of the above variations.
The Apr. 14, 1925 patent can be found on DATAMP with links to the others.
http://www.datamp.org/patents/displayPatent.php?number=1533602&typeCode=0This self adjusting style of wrench was very popular, besides the Einhander and Cleveland already mentioned there are probably nearly fifty other brands