Tim, Richard from down under and I have been sharing info via email for the past year. I have been compiling pictures and sending him of the details I've been finding as I restore these structures. I will be sending him a flashdrive soon. Even in his post where he mentions the main side rail hinge being cast up to 67 will need to be changed as I have a 67 top downstairs which has the 68 pin version. Must have been a running change mid year. The hinge is a quick identification point but there are parts which differentiate the 64.5 to 67 as well. There are differences in the header verticle strakes, chrome catch mechanism profile, latch handle mounting point to the header, scissor mechanism markings, fastener differences used at #2 bow connection to the side rail mechanism, the #2 and #3 bow end brackets, bolt type used to connect rear side rail piece to the intermediate side rail, #4 bow differences and even found that the 64.5 uses smaller bolts to mount the cylinder access plate at the main mounting bracket than a 67/68. Granted I only have pics I took of a 66 and 69 structure but I will study the 66 pics to see if its even different then the 64.5. I will be sending all the pics to Oz shortly but figured i could share some of this here if people want to see pics versus just verbal descriptions. but is it worthwhile to just post as a thread?