>> In terms of longevity, performance and utility, I can think of nothing that comes even remotely close. First built in the 1930s and still almost fully competitive with the most advanced current gear.
I'm no expert on prewar gear or what components were on the market the longest, or had the greatest functionality or utility, and I certainly admire the design of the 49D. But might I respectfully suggest that the Brooks B-17 be considered as equal or superior to the 49D in these regards, considering it was introduced around 1898 and is still in production... and aside from its weight, it is certainly competitive with the best current gear in terms of comfort, durability and value.
>> I've uploaded a collection of photos that will hopefully illustrate most if not all of the general variants that can be seen and perhaps referenced to provide examples useful to this end.
Kurt, that's an excellent body of work, very nicely done... I can't wait to look the photos over more closely when I get off work. The 49D in all it's variations certainly was a beautiful component. I hesitate to suggest this, given the already considerable time and effort you've invested, but is there a possibility you might add a caption or two, perhaps with dates and some notes on the design details?
Columbus, GA USA