[Mgs] '71 MGB Prop/drive shaft bolts and nuts -- use Nylok or regular nuts?

[Simon Matthews]

We just removed the prop shaft from the '71 MGB GT that my kids drive.
According to my Haynes manual, the prop shaft should be held in place by
bolts that are inserter through the flanges of the propshaft first, then
through the flanges on the gearbox and differential, with the nuts on the
outer side.

What we found was that the bolts were inserted the other way. In fact, at
the gearbox end, after removing the nuts and pulling the propshaft of the
bolts, the bolts can not be removed -- there is not enough space. These
bolts have a circular head with a small segment removed. When pushed fully
in the removed segment meshes with something in the flange and stops the
bolt from rotating.

While removing the prop shaft, we  found Nylok nuts while the Haynes manual
shows regular nuts and washers.

Is it sensible to replace the Nylok  nuts with new Nylok nuts? Or go back
to what the Haynes manual shows?

The rear universal joint had completely failed - to the point that it had
also damaged the shaft where the U-joint fastens into the shaft. It is just
as well that I had ordered a complete new shaft when I noticed some play in
the U-joint while adjusting the brakes!

Simon