I use a new percolator, rather than a vintage one, but the method is the same. You'll need to experiment for a while to get it right - the right amount of coffee grounds to water, the right amount of time to let the water seep through the grounds - but once it's right it's every bit as good as a French press and the coffee stays hotter in the pot as well. The coffee needs to be ground slightly coarser than for a French press.
This is what I use if it's just me drinking coffee, a Bialetti Amerikana (but in red):
It has two water levels, minimum and maximum, and I fill it with water to the maximum level, then add three spoonsful of ground coffee to the basket. Put it on the heat then once it's perc'ing turn down the heat to medium and leave for exactly four minutes. This makes three small mugs of delicious strong, rich and hot coffee.
I really want coffee now...