Meant to be Seen

I've a Redrover SDM-240 passive 3D monitor arriving soon - it uses two monitors with a mirror and needs linear polarised 45/135 glasses. I can find one source of these in the UK, but it's not exactly cheap, and I'd like to prove everything works before buying a high end pair of glasses.

Is there a pair of glasses, off ebay or similar, perhaps one of the identifiable older IMAX ones (I know some were 45/135) that can be used without dropping fifty quid on a pair? Yes, I can find lots of glasses but most are circular polarised, and most of the IMAX ones will be too as the technology has changed.

IMAX can be any of circular polarisation (most recent), 45/135, or 0/90 depending on the technology. It seems difficult/impossible to tell the difference, which is why I'm asking if anyone can reliably identify suitable ones.