SJS has all the Brompton spares .. Get the one made to go in the brazed on clips of the all steel model

FWIW with my Bike Friday the punp goes into a pannier I have on the front rack .

Like the Brompton they handle best IMO with some weight on the front wheel..


Where I had the room I have a long stroke Frame pump , but sacrifices are made to make thing small

along with your spare tube and tire removal tools maybe one of those CO2 inflators will work for you.

You can also buy Presta valve tubes , if that works better.
(no return spring in the valve core to push open with every stroke,
just the air pressure increase over what's in there, closes the check-valve.)

Where dynaryder fits that Topeak pump needs pictures , unless its also put in the front bag ..