New master cylinder questions

[Beekeeper]

I'm in process of cleaning and restoring my pedals in my 69'
bee. I found that the master cylinder is leaking a bit around the rear seal so I'm gonna replace it. I plan on changing to discs in the front at some point. Now it's manual drums around. So thinking if possible to install a master cylinder
compatible with drum disc setup but would that work with drums until I do the conversion? And what master do I need for disc/drum setup.

 

[65-440]

How far down the road is "at some point" ? I use master cylinder dbmc15 from right stuff detailing. Use it on my 70 swinger and 68 Coronet, both manual front disc. Check summit, they carry it.