It seems this prop was made in-house by ILM for ROTJ.
I suspect the parts used come from kits that ILM was known to use during this time period.
The side detailing does look like tank tread, but does not appear to be the same 1/48 Panther tread used on the Thermal Detonator prop.
What other tank or treaded vehicle model might this have come from?
I don´t have access to these models and only included them in my "watch-list" because of the few pics of built tank-models I found online. The listed models seemed to have the special tread.
Besides of that I don´t think we´ll have much luck tracking down the parts because the Lando blaster isn´t of much interest for most of the prop-builders IMO. Less interest = less attention to this thread = less chance to identify the parts :cry