Fallowing conversion set for Manfrotto 405 and 410 gear head I did machine similar plate for Manfrotto 808 3-Way Pan/Tilt Head. This combination of plate and clamp (F63) will let you use Manfrotto head with any arca swiss equipment.
After removing lock down level on 808 head you can connect conversion plate using two 10-32 flat head screws.
Clamp at top of conversion plate can be oriented in three different direction. It can not be oriented with knob facing bubble level.
available in my store