Fig. 77 shows the Indestro decal on the lid of the No. 1536 set, though it's a bit difficult to read due to the glare from the finish. This decal is identical to the decal on an earlier socket set, examples from which were shown as the Early Indestro Sockets above, so apparently these sets were sold for some period of time.
One additional note regarding this set: of the tools in the set, only the ratchet handle had an identification mark, and that was only the patent number for the ratchet. If the decal with the Indestro logo case were lost or obliterated, or the tools dispersed from the case, it would be difficult to identify them as part of an Indestro set.
Although the sockets in this set are marked only with the size, the Indestro catalogs did assign model numbers to the series, similar to the numbering used for the Duro D-Trapezoid sockets described above. The 1937 Indestro catalog (p. 26) shows these sockets in a table "Master Sockets", with model numbers of the form 66xx where ** is the size in 32nds, e.g. 6624 for the 3/4 size. Similar to the case for Duro, the square and double-square sockets have a "-S" appended, e.g. 6624-S.
While we're mentioning the Indestro 1937 catalog, it's worth noting a statement from the catalog that may prove significant for a later discussion. In referring to the "Selected Steel Sockets", the catalog states: "The Sockets are accurately broached and the heat treating, tempering, and hardening is done under our own supervision, in our own factory ...". Note that the careful wording doesn't say that Indestro actually machined the socket blanks.
