Well you can pull apart an old tail lamp and pinch the bulb holder from it
Slip a 1 Watt resistor in the wire to the tail lamp then introduce the stop lamp on the globe side of the resistor
Fit a bright globe
Both have problems
First one is finding a bulb holder that will fit .
And if you do be careful to fit a offset pin type because parallel pins are period corrct but it is hard to find stop=tail lamps with parallel pins in 6 V and near impossible in 12 V
However you can run LEDs which work so much better and are a lot brighter
Using a resistor make the fewer changes and is easier to do plus you only end up with a single wire entering the lamp base which keeps the rivet counters happy
(Or 2 if you run extra ground wires )
However running a bright globe at less than full power severely limits their life as tungsten resistor wire is quite frail any where between off and bright white heat .
Yon can also not use LED's