I decided not to fume the sapele.
Actually, I was going to add a small sample to the tent while I was fuming the oak, but just forgot about it.
So, the 9.5% stuff finally arrived, I finished the fuming tent - ugly, but no leaks, and had a go.
I didn't know how much to use, or for how long, so tried about 150ml in a small dish overnight.
The top reacted much stronger than the legs, but I had an idea this might be the case.
I should try and colour match the photos for a better comparison.
It's gone much greyer than I expected, but has nicely hidden that blemish at the top right. We'll see what it looks like after some oil.
I hadn't considered what the dowel might look like after fuming, and it really stands out. It's generic 'hardwood', and has no grain whatsoever. Does anywhere sell named wood lengths of dowel?
A 3/4 view of before: