Timing Tensioner ? ? ? ?

Hello all , i am rebuilding my standard 1200 sedan motor and have every thing except for the damn timing tensioner , the ones that all our part suppliers (in Australia) have listed for the TB engine dont seem to fit ....(boom07) the part i am after has no part number but has a marking that says

RENOLD
GREAT BRITAIN
BRIT.PAT.No724522

any assistance in finding one of these will be greatly appreciated as this is the only thing holding my restore up ...PLEASE i want my Mazzy back on the road ...

Thanking you all kindly ....Phil