I have to set something clear now:
We are in 2012.
Neither the flatheads nor the roundheads produce espresso.
They simply don't.
They even didn't in 1948... so imagine, in 2012!!!
They are Moka pots.
Moka pots that are able to froth milk.
Nice looking Moka pots.
Of course, it is up to you to do whatever is in your power to increase the pressure.
May it be, like advised on this leaflet, to pack the coffee in tight.
Another solution comes from Giordano Robbiati's U.S.A. patent for a, i quote, "Coffee Maker":
Cut a filter paper to shape, and place it on the bottom of the coffee holder.
But may i comfort you:
You won't make it to 9 bar.