Here's the BMW style friction damper I built recently. I know it is not practical, and I know hydraulic dampers are much more efficient. That said, I wanted one, so I built one. I think it looks cool.
Don't sell yourself short mate, most bikes built before the 1970's ran friction dampers like yours, and they worked well. In fact, somewhere in a box I've got a NOS Ceriani damper I bought on eBay a few years ago.
One advantage a friction damper has over many hydraulic dampers is the constant damping available, whereas many hydraulic dampers have some slack before a "take up" point, much like if you took the fork springs out of your forks you'd have a certain amount of travel before the damping becomes apparent. Nice work!