It's raining here today so I'll have to measure it another day.

I'll get it as soon as I can.
When I was talking to Scarebird about making a rear disc brake conversion kit they told me that the housings were the same from
like 1960 - 1967 or something close to that. Maybe they meant for the purposes of a disc brake bracket but there may be other
differences that wouldn't matter to them (like suspension mounting points). But I think you'll find that they are very close.