GOT IT OUT!! 😀
Undamaged, apart from a couple of scuffs but perfectly useable too.
Been spraying WD40 down the inverted frame for days and then on Saturday I plugged it and filled it with diesel and left it to soak. Stuck it in the bench vice yesterday and got it turning in the frame and then popped an old saddle on and my wife gave me a hand to screw it out of the frame. Some of the black anodizing has come off the inserted part but that’s a not a problem. Cleaned it up, blathered it with Waxoyl, car body underseal to avoid any other kind of corrosion, and popped it back in.
I’ll be popping it in and out regularly from now on (ooer!) 😉
Didn’t get a ride in this weekend but just happy to get that sorted.
Thanks for all the various advice everyone.