Ok i removed all my post & the video that were totally wrong with me thinking different forks.
Pics in above link is an old set of similar forks if you can follow my pics.
But in the end i guess Marks idea is best with gator grip i'm not familiar with.

I'm getting worried now if all thats stopping the forks coming apart in mid air over a jump is the roll pin going crossways holding the top on the damper tube.

Thanks, The top of the damper appears circular but with flat sides. I presume this is what you refer to as "Flats". 
I'll have a look at the Gator grip option.
Appreciate your advice.

Yep that's what shows in my pic link above--two flat sides-- & a 16mm double hex socket worked good. Remember you're just holding it still & turning the Allen key not turning the damper.

How do those gator grips work. Do you just remove pieces until it fits. What holds them in from dropping out. Are they magnetic or magic. I'll go find me a video.

Might find some steel pipe today & squash it flat-ish to give two flat side. That could hold it still. Do you have an air or battery impact rattle gun with an Allen socket. Hold hard against the top out Spring while spinning rattling left & right. It'll undo unless super loctited in which sounds like it might be in your case.

Once I got my first set of forks apart I promptly made a tool on an extension to stick down the tube and catch the flats.  Once apart you can customize a tool to fit exactly. Gave me an excuse to get the MIG out.

i.imgur.com/fYIxLdk.jpg
   Here you go RT325 it works good on rounded bolts or nuts 

Cool, thanks Ht1kid.
Started sorting my shed but got sidetracked on the seal removal again.
Have seen someone possibly on here with a good idea to pull them out.
I cut a heavy washer but couldn't get it in then set straight. Kept cutting until it did fit but terrible guesswork cutting. Did pull it out though.
Thought refit it again & peel the rubber off with a screw driver to get a good pull on the steel & also a decent size washer should go in & tilt straight.
I had to go past the seal to get my original cut washer in so of course it wouldnt go straight as too big, not enough room & rubber got in the way.
So another attempt--# whatever, pulled it with a washer that had a 6mm thread so it tried to stay rigid & worked ok & with no rubber its straight on the steel.
But as i said, maybe cut a washer big as possible with the seal rubber scraped out so it will fit & tilt hopefully getting under enough to pull square on.
Hammer Puller is a genuine yamaha puller for pulling the rocker shafts out of a TT250 head. Of course i've used it for just about everything it wasn't designed for haha.
8mm shaft with a slide hammer might be best, & a bit longer than mine. 
Ok photo link attempt, hope it takes.
photos.app.goo.gl/o4Aw1Bni8jRzjKfB6
All looks pretty rough--& it is!!

Thanks this is really helpful. 

Sorry to keep this going & i'm sure it's someting MarkT has considered, but what is the OD of a Gator thingy.
I just measured the damper part that runs in the fork leg & measures 25.7mm so clearance on that say 25mm. My 16mm half inch drive socket measures 22.3mm.
Sorry Sorry, found Marks earlier post & about 25mm OD.