Still have the DIY frameset I built in the 70's, I did make it myself from tube set upward, so Its a keeper..

though the components are different on the ones I use, most now .

It has Derailleurs, and I seem to use my 2 internal gear bikes more:
a Rohloff hub trekking bike, groceries in the panniers.. fussing over the fit does sort of make it custom..though a factory bike.
and a Sturmey AW3 and Schlumpf MD crank . in my Brompton folder,Its a one size only bike folds up small ,
got the both of those Used.