My reba is lying on the floor next to me right now, but not in pieces as I'd hoped. I've PP's guide to removing the travel adjust spacers and have followed it to no.5 (emptied air chambers, unscrewed bolts on bottom, whacked rebound one, came loose fine) but I can't get the neg. air valve to budge no matter how hard I hit it. Am I right in understanding that it should disappear up into the lower and I'll be able to remove them then?

Just did a mates Revs and I think they are the same. Yes, if you've let the air out of both chambers the valve should come loose with a reasonable tap, it doesn't disappear, just gets loose.

Doesn't feel lose. I'm trying to pull them apart from the crown and brace and they don't budge past past the normal topout (the rebound bolt is removed).

The worry is always damaging the valve.

It's difficult, but I have succeeded by pulling them apart first then giving the valve a sharp tap whilst keeping the pressure up. If you see what I mean, but you will need an extra hand, or hook the crown round a large object.

hit it harder

Girlfriend's hand proved very useful (as did hitting harder, several times) 🙂

Now I'm just a little angry. Bought the cheap Reba SL from Merlin which was advertised as "All Travel Adjust". Is it ****. Any chance they'll placate me considering I've already cut the steerer and ridden them a few times?

There is something that looks like a spacer. I found a picture on google of what it should look like but mine is at the bottom of the stack and not the top. It's also solid, so no way to remove it peacefully.

You need this:

http://www.sram.com/_media/techdocs/2010%20RockShox%20SPC_Rev%20B%20(Rev%20B%20price%20list)%20.pdf

Thanks, I had that already but appear to have become temporarily blind to simple instructions. Who woulda thought you just had to slide it off? 😀 If I'd just stopped a second and thought, it would have been obvious. No more wine and fettling for me.

Thanks to everyone who offered help. I'll go and hide my shame now.

Oh, and Merlin are great. They did send me the correct fork and I'm an idiot.

Ah!

Fettle Blindness. A well known condition.
😉