420 Radius arm bolt removal – advice please.

[BookerME]

I can’t see how to get the bolt holding the radius arm to the suspension unit out. I’ve dropped the hub carrier off of the wishbone – it was much easier than I remembered and I’ve undone the self-locking nut holding the bolt holding the radius arm to the wishbone.

I was half-expecting to see some sort of bolt head on the inside of the wishbone but there’s nothing, it’s a round bolt head flush with the surface of the wishbone.
I’ve tried a lever against the nut, having wound it out enough to prevent damage to the bolt thread but it won’t budge. Both sides are identical, so it's unlikely to be an historical bodge job.

I’ve two workshop manuals.
The official Daimler one says simply ’remove the self-locking nut and bolt securing the radius arm to the wishbone and remove the radius arm’.
The Autobooks one says ’remove the self-locking nut and special thin-headed bolt securing the radius arm to the wishbone’.

Does anyone know how this bolt is held in place please?
Has anyone got any advice on how to get it out please?

Cheers, Mac.
Pictures below. The loosened nut on the bolt. The end of the flush bolt inside the wishbone.

[BookerME]

I've just seen on an E-Type posting that the bolt might possibly be threaded into the wishbone?
Maybe I'll see if I can get two nuts on the bolt locked against each other and see it it'll move with a ring spanner.
There's not much room to work in though....

[BookerME]

I got them both off eventually.
Drop the hub off to get access to the bolt head which has a thin hexagonal head and is inlaid flush with the surface of the wishbone. At first it appears to have a round end but it doesn’t, it’s a conventional bolt head.
Undo the nut on the other end, packing out the gap between nut and the shock absorber mounting. Then as the nut is undone it pushes back against the bolt. I had to put some heat on the bolt head with a gas torch, then just unwound the nut. Both bolts popped out.

Cheers, Mac.