Thermal expansion of wood is much smaller than expansion due to change in water content.
You can calculate the change in relative humidity upon taking air from 10 - 40 degrees, but this assumes a closed system, which is unlikely to be helpful. This will change the water content in the wood...
If you don't want to use the space above the ceiling, fibreglass insulation will probably be cheaper and give better sound proofing.
You'll need a moisture barrier on the warm side.
I have a green one. Think I paid about £30 at some point in the last year or so.
No idea if it's significantly different (colour aside) to the Axminster version.
I find a parrot vice (with wooden jaws) to be useful for holding awkward stuff. No good for really large pieces, but could be used to hold the piece in the OP.
Yes, adjustment doesn't work nearly as well as the engineers clearly thought it would.
Something else to watch is that you set the iron so that it is hard against the side/ wall of the casting. Or at least, that seems to work for me.
If it's anything like the bamboo flooring I installed 10 years ago, it can splinter quite badly. Seemed to cross cut fine, but ripping was a bit of a chore.
I thought he was an advocate of diamond plates, which are low maintenance and certainly don't need flattening (no idea how you'd sharpen them).
For what little it's worth, they are my recommendation.
New Mills - wrong side for a quick trip to Lincoln.
Edit - sorry, never mind. The cost difference to get a new one delivered makes the effort hard to justify.
The wooden ones don't have to be curved. That was done for aesthetics.
That said, you could shape them with a file, sander, spoke shave, chisel, etc, etc.
+1 more for BLO or similar.
Only thing to note is that if you put BLO on too thick, or don't wipe off excess after applying, it can remain a bit sticky. Helpful in terms of stopping stuff sliding around, but makes cleaning off the sawdust more difficult.
A top coat of wax sounds like a good fix...