Personally I question whether some of the entries so far are really presented as downhill bikes even though the frames were used in downhill competition in their day.
For example is a bike with:
a long low stem,
narrow flat bars,
saddle height way higher than the bar height, and
a triple chain ring.
really a downhill bike as presented?? Sure you may have raced it like that in a local race back in the day but calling it a DH bike is stretching things just a little considering they weren't raced setup like that at the higher levels of DH competition.
I'd be expecting to see at least some of the following on a DH bike depending on its age and based on what the DH articles called DH throughout the ages:
a lower saddle,
some form of chain device (be it the useless long spring things which fitted to the rear QR and help tension the rear derailleur, to chain stay rollers etc)
Maguras either on both ends or just the rear
some early form of disc brake, sometimes just on the rear
a chainring the size of a dinner plate (with the granny removed even if the middle ring was retained)
Anyway this isn't meant to be too critical of any bikes and their builds but simply a question 'Is it really
a downhill bike?'