As far as I know, all of Curtiss Hawk 75 (without Hawk 75-A1,P-36A,P-36C,YP-37) could carry 136 kg bombs under wings. The M,N,O version additionally 227 kg under a fuselage.
Avia B 534 - all of its varieties could carry 6X10 kg or 4X20 kg bombs
The Gloster Gladiator from what i can find is not shown as having a bomb carrying capacity. Im sure i have seen photos of them carrying bombs though. I would guess either 4x 50lp or 8x 50lp. Maybe 100lp.
SlickDriver and Crowdpleaser are absolutely right.It is not possible to find out about bombload of DXXI.I was looking for it everywhere but with no success.