I don't collect hammers, but somehow ended up acquiring these (29 plus
a few that missed the picture), all I think in 2016. Nothing very
exceptional here, I guess, but cumulatively they begin to take up
a lot of space. And prompt a few questions. Inquiring minds need to know.
(1) B3 has the full ATHA TOOL CO logo. Was that ever used
after the company was acquired by Stanley? I.e., is it
safe to date this pre-Stanley?
(2) There are two Stanley/Atha 780s here, one with the Atha
logo, one without. Is the latter likely to be later
than the former?
(3) B.L.Marder (B6) is not a company I'm familiar with, though
I see examples online.
(4) The items with asterisks in the list have the dreaded
"Wear Safety Goggles" instruction. What year did that
come on the scene, anyway? Is it a useful dating criterion,
aside from meaning 'recent'? (e.g. like a book with a 9-digit
SBN is probably 1968-1972; one with a 10-digit ISBN is post-1971.)
(5) Anyone recognize the "DS & S" or "DS & SH(?)" on the mean
6-1/2-pound cast slab of a hammer (T2)?
(6) T13 is a curiosity, I think: probably a shop project. The
ball-pein head and the handle are both solid polished steel
turnings; the handle screws into the head.

Bottom row:
B1 "4 ROCO"
*B2 "USM 4"
B3 ATHA TOOL CO CAST STEEL 5
B4 True Temper
B5 [unmarked bronze]
B6 B.L. Marder Co. Chicago (F) DROP FORGED
B7 [unmarked small claw hammer]
B8 [unmarked perfect-handle-type, face w/some chips]
B9 ARROW
B10 [cobbler's hammer marked only "DROP FORGED"]
*B11 STANLEY 16 oz.
B12 STANLEY 780 - 3 LB. with A-in-horseshoe Atha logo
B13 STANLEY 780 - 3 LB. (without Atha logo)
B14 [unmarked cobbler's hammer, looks rather old]
Top row
*T1 Warren-Teed 84-6
T2 6 1/2 LBS (triangle logo) DS & S [maybe DS & SH?] WARRANTED
*T3 M 2 1/2
T4 PLUMB
T5 HELLER MADE IN USA 8 oz.
T6 CHICAGO RAWHIDE 2
T7 PROTO 1448 LOS ANGELES MFD USA
T8 [unmarked cobbler's]
T9 [only an owner's mark: "JACK OMALLY"]
T10 HE 5 GARLAND No. 8 SACO MAINE
T11 [no markings, plated]
T12 BEALL BROS ALTON ILL 4
T13 [shop-made, solid steel turnings]
T14 [no markings]
T15 FAIRMOUNT