I am not famous for being able to read hand-writing or signatures but this is one of the most legible signatures I have seen. I checked it with a magnifier dozens of times before posting and again now. I am absolutely sure of the surname. Each letter is independently legible. The only one I have the slightest doubt about is the b but I nothing else fits or looks remotely like it but just in case a friend kindly tried googling Roblatt, Rowlatt & but to no avail.
The photos are all pretty dreadful but these are the best I can do. I took loads of shots and tried various editing treatments but the base is very scratched and the scratches get highlighted as much as the signature itself.
What does become clearer in the photos, but to my naked eye looks like damage, is I presume, the date: '68. Looks like his drill lost sharpness as the crosses on the T's are similarly gouged. Thanks for looking
Peter