The nosecones.
P115: no problem, built OOB, a part of reducing the inside of the nosecone to let the fitting:

On the left the green arrow shows the work already done; on the left the tickness of the original nosecone.
Here the final result:
P83: here Stewart at Spa:

as you can see, inside the nosecone there were some flaps which Hiro didn't make.
So I made a mould of the inside of the nosecone:
Then I wrote with a pencil the shape of the flaps; the nosecone in the pic is that of the P83 of Spencer at Monza:
With 0.2 mm plasticard I made the flaps:
Here a fitting test:
After painting with semigloss black and washed with dry aluminium, I glued the two parts inside the nosecone, in front of the mesh:
Here the two cars together: