Thank you input gentlemen. 

I intended to remove swinging arm to jig the frame. But, would have needed to destroy the spindle and bushes. The is a job for the future. That job needs doing as the rear engine mount in alloy has some play on the spindles and also slides about 2mm from center either side until it abuts the swinging arm bushes. 

I ended up jigging the 3 engine mounting bolts with box section mild steel tube, and centered it in the mounts on all 3 with the rear engine mount lying horizontal. 

Manufactured a half moon section dolly, and used heavy club hammer to beat lower tube back into line:n and refitted engine to ensure that frame tubes clear engine: it does, and appears approx equal on both sides; the clearance.

Top frame tube is bent out of line so have booked in an appointment with motorcycle frame alignment workshop. I suspect that frame front downtime is also bent a tad. 

Ongoing, but may take awhile. Would like to have it MoT and road legal by April: it is road registered and I have V5c. But if I wait until end of May it will be MoT exempt as well as road Tax free.

Hurrah! 

Thank you, they do needful looking at as the alloy rear engine mount is "floppy" and not clamped up firmly between the swinging bushes. Loose, but not rattling.  And these bushes are seized on the spindle.

I suspect it's should be clamped firmly and centered in the frame. Is that correct?

Many thanks, jj

The ag bikes alloy swing arm is a copy of a works bike. Ag has the actual bike in his collection. Ag bikes are located in north yorkshire uk

On 09/01/2018 at 9:05 AM, jonjeans said:

Thanks for input, will give it a go.

My frame tubes were like yours ‘well dented’. I cut them out and made replacement tubes and welded them in place. Previous owner had deleted the useless bash plate and fitted an alloy version, didn’t save the frame from his rock bashing riding techniques though? when you fit the engine back into the frame install some thick rubber mat to absorb impacts and note onto engine cases. Mat should not be over frame tubes.