For your consideration ....
Compared to the Lionel-AF reissue the Gilbert original 24323 has a darker gray, a matte white finish, a bit more detail on Mrs. Baker (an applique), lower trucks, gray-painted handrails on the dome platform, and a black ladder. Complete tank vs. split tank. The sharp-eyed will also notice that the two hazardous materials markers are both on one end ... a common but not universal Gilbert mistake. The markings differ, as well, with the lettering being sharper on the new reissue. I know which one I prefer, but I will leave that judgement to you all.
Have fun!
Bob