You can see from the bullet holes & pools of blood on some of the transfer figures that this set is as 'gory' as the "Kung Fu Kombat" & "Tarzan of the Apes Battles the Catmen" sets, both in the same GK173 range.
We haven't yet seen any evidence of 'vanilla' version of this sheet; it's quite possible it was cleaned up, but on the other hand, preparing gravure rolls was very expensive & that would count against a revision.
However, there is a different transfer sheet from a later set in which some of the figures from this sheet appear, & where they are definitely cleaned up…
Four years after "Look Out Gotham!" appeared, Letraset produced a set (L80/3) with no title other than "Batman", which combined artwork from both the "Super Action Heroes" Batman sets (the other set being "Batman: Gold Diggers of Gotham City").
This 1978 set was litho printed. I can't yet show you in detail the transfer sheet from this set, because I am waiting for it to arrive for scanning; it should be available very soon. Meanwhile, here is StellarX' "7 Wonders" version:
It is not in the least surprising that when Letraset reprinted the two Batman SAH sheets as a single untitled "Batman" sheet, they made changes to the artwork. To print a new sheet for litho is simplicity itself, & the cost is negligible. But to have to reprint a gravure sheet with even a minor alteration would have been very expensive; so until we actually see the "Look Out Gotham!" set with 'vanilla' artwork, we can't say either way whether or not it ever existed.
Picture Credit: The SPLAT Scan Archives
© Tom Vinelott 2017