Well a joyous afternoon....
worked that big delve out of the rear corner, couldnt quite get it 100% out but it will only take a smear of filler to be right n ow

it has the correct profile now

right the inner arch, the rear i have rebuilt, will take picks tomoz and add as i forgot
this next bit i have tacked with gas, its about as quick as mig yet a smaller weld, it doesnt matter if its not perfect fit gap wise as it is easy enough to fill with weld,
the grips are there so that when im welding i hook a finger round the grips and have the welding rod in the rest of me digits and its like co-ordinnated , i need to lift and push the grips to move the join to aid welding and with the same hand feed the filler rod, sound complicated but easy once you get the hang, be easier if i had a sprog to assist but ,,,,,,,,

here is a better look at the tacking

front edge, they usually go here as well, in this case not as bad as some, the rest of the inner through to the cab is fine

from the wheel side, i will give this a quick run with a disc, it shows penetration is fair

so its complete now, needs trimming to fit clean to the inside of the wing is all

sanded over, it doesnt need to be any neater here as after treating and such it will not be noticed

quick dob of weldthru

same here and a light coat to prevent surface rust

so that was one way of doing the job, im open to thoughs on other ways, personally i prefere cutting the rear 1/4 off and doing it that way but in this case the lower area behind the 1/4 was ok so it seemded a shame to destroy good metal and removing the 1/4 would not be possible without chopping the floor so to speak.
away tomoz so thurs will fit the wing and then slider bottom and outer sill, easy peasy

then its front arches and detail bits and bats and into paint, at least im fairly happy that the pertinent rot has been removed
mm