Looks like you got yourself a 200S cabinet. Must be a later one, looking at the grill cloth.
That cabinet was designed - dreamed up, actually - to use the JBL D140. Those are not all that easy to find, and tend to be pricey. Vintage alnico drivers, collectors love 'em. K140 is a very similar driver. Some say they're identical. The E140 is a later, ceramic magnet driver, but I'm sure it would also work well.
As for modern drivers, I can't say. You might try to match the T-S parameters as closely as you can. Here are some that are said to be for the D140:
Vas 10.5ft3
Qms 5.0
Qes 0.22
Qts 0.21
Fs 30Hz
Sens 98dB/W/M
Max Power 150Wrms
I can't vouch for the accuracy of them, except for Fs, which I've measured on my own D140s. Note that Max Power is not RMS.