Judging by what you already have, you seem to like quite classic looking, time only type watches.
I would have recommended a classic speedmaster hesalite on a leather deployant but failing that here are some other options
Cheapest
Hamilton Khaki mechanical field watch
I think about 38-39mm - versatile on a nato
around £400
Classic time only
Step it up
Bremont just released 3 UK MOD pieces which i happen to like which are classic time / tool watches
3k for the broadsword MOD watch - date and small seconds
want to get a bit more technical
4k for the RAF pilots watch with chrono
Bigger too (similar to speedy)
Which brings me onto classic pilots watches by IWC
smaller
mark XVI
bigger
mark XVII
p.s. still think you should consider a speedy
😀