Screws for fitting Traveller rear wheel arch to rear post

[splitscreen]

Can anyone tell me the correct screw type/size for fitting the rear wheel arch timber to the back post please.
I've seen the article in Minor Matters re the different timber sections and the fixings here look like standard wood screws. However from what I can see from the remnants of the original fixings I have, there appears to have been a threaded insert into the post into which a bolt passing through the wheel arch timber was fixed.
Any help here from those that have undertaken timber replacement would be appreciated.

[simmitc]

If it's the one I think you mean, then 2.5" No 8 c/s. Not too critical, as long as it grips and does not protrude through the other side, it should be OK. The threaded insert is how the wing was originally attached. These days people tend to use screw type fixings straight into the wood, but from the factory the inserts were put in the wood, and the wings held on with bolts into the inserts.