Grahame, I have had severals things to make conversions for and with parallel inner up to a shoulder and tapered outer and split to work, that could be to save a nasty accident. if working in opposite with tapered inner and keyed the outer but if you split the bush it works even better as long as the driven part has a good strong boss. On some early cars? well can think of one in the late 1960s used rear wheel hubs sitting on parallel shafts. It didn’t work in the early cars so never worked in the later ones ether and it stressed the threaded part of the stub by bending until it breaks and wheel takes a hike and if the brake drum was with it even more excitement as no braking. 1905 Rover all suffer, with slightly different as has to have part taper as outer part not strong enough to take the stress and if kept to a shallow taper would be very difficult to pull off in the future, so shaft needed to be held tight but not to stress other parts. So its a good safe repair if thought out.
