This could be a TH3535?
Datasheet here.
The design is not exactly the same (1 truncated corner, the other corner seems to be gold plated), but maybe there were changes in production process or something like that.
It could also be maybe a Lumileds HL2X in cool white? The die size would match perfectly, also it has 2 truncated corners. Since the HL2X has not been the most widely used and some types have already been discontinued, I could imagine that they are available at very reasonable prices, depending on the quantity purchased and CCT/CRI.