What a great trike frame.
I agree with the people saying to keep it conservative for your first build while you learn. Clean it, paint it, get the drive train and brakes working, new wheels and tires if you need them. That's enough learning for a first time. Especially on a trike where a lot of the standard information won't apply.
Then once you've got a rider you can enjoy, start planning a crate for the back, outlandish forks, electric motor, whatever.
You can rebuild it as many times as you like the whole time you own it and love it.
But if you burn out on your first build trying to get a fork that fits and none of the information on the internet seems to apply, and it's only after you buy five different headsets that you find out that your bike is from a specific region and era, and for six months in 1967 every bicycle built in Toulon, France was made with a head tube 1.349mm smaller than the standard, that's when it ends up back on the curbside and you never touch another bicycle again.
