I have only done a round nose, but I fitted subframe and bolted front panel to it, left loose, then fitted bonnet with correct gap to scuttle and fitted bonnet catch to front panel, then adjusted front panel so bonnet all lined up. Then trial fitted wings held with self tappers. When I was happy I removed the lot and spot welded wings to front panel off the car, then refitted and spot welded wings in place. I found it easier to fit wings to correct gap to bonnet, then any twisting and bending to reach the a panel and scuttle correctly left the gaps intact. Takes a good few hours to get correct but worth the extra time.
If my subframe was rubber mounted I would have used the stock mounts, the main location is to the crossmember.
Hope that helps.
And as a matter of interest I have found heritage panels no easier to fit than magnum ones. Although I would always use an original bonnet and scuttle.
Edited by Daz1968, 23 June 2018 - 02:45 PM.