I ran across this anomaly by accident the other day. I was looking through some of the old Choppers
Magazines, looking for photos of Tom Burke, Junior, Motor Mouse, and Pat Leahy - all alumni of Tom's shop, B&O Cycles in Long Beach, CA., for a couple future posts. Chris Bunch, the then-editor of Choppers, spent a lot of time hanging out at B&O back then, and Tom's shop was one of his "go-to" places if Bunch needed a tech article done/photographed for the magazine.
In the April, 1973 issue, Bunch did a feature on Motor Mouse's fresh build, with a '64 Pan/Shovel combo for power. As I was looking at the feature (and I've looked at this dozens of times over the years), I read the part of the article that said "Up front, Mouse chose an early (Note from me - notice it said early) Dick Allen 15 over springer, which runs on an 18 - inch tire and spool hub". Then I looked at the photo of Mouse's Dick Allen springer on his bike again.......do you notice what I did? Look at the distance separating the top springs.....it's a Dick Allen-built WIDE springer!

I pulled this photo out of Joe Hurst's article on his White Bear bike out of the July 1973 issue of Street Chopper. Joe's DA springer had been on his bike since '68, so if there was an early DA front end (besides Dick's), his would be a good example. The thing the early DA front ends were noted for, was narrow. So narrow that a Buchanons spool hub barely fit between the rockers. Take a look at the spacing between the upper springs, and the round bar (the most common) spring perch for the lower springs......
Now, look at the spacing of the upper springs on Mouse's DA front end. See how far apart they are? Dick built Mouse's front end just about as wide as an original springer was. Also note, that the lower spring perch bar is square - not round, and about as thick as the lower triple tree is.
I "borrowed", as you can see, part of this photo from the MC Art blog, to show how close the rockers actually came to the front wheel's hub on the DA springers.......
Now look at the spacing between Mouse's Buchanons spool hub, and the inside distance between the rockers on his DA front end. The spacing here is about what you's find on an original springer.
I've seen all kinds of Dick Allen springers, and sure, Dick was building these one at a time, and yeah, I'm sure if you asked, you could probably get one any width you wanted if Dick was in the mood to accommodate you. I've seen several DA springers that are a little wider than Joe Hurst's, but not much. This is the widest Dick Allen springer I can remember ever coming across, and also being referred to as being an early built DA springer to boot.