depends on the kinda dropforward you already have.
on most you can detatch the actual donkey (the bit the bottle screws) into from the drop forward.
if you can, try screwing it into place then putting the donkey back on the drop forward. you may find that you can screw the bottle on in such a way that the dial is facing out to the side, or down away from the drop forward, and therefore the donkey will fit back on the dropforward without obstruction
It does mean that you cant take the bottle off for storage without repeating the process, but it is the cheapest option.
beyond that, new smaller dials, or a deaper drop forward.