The 'lollipop' plastic POS that comes with the EzyBox and is needed to mount the actual box part to anything has a big slot in it to fit a speedlite. Trouble is the slot is way too narrow in height (no problem with a dremel) but more importantly, it is too long/wide to fit on the four arms of the Alienbee.
You would need to make a disc the same size as the 'lillipop' and cut a circle out of it the right size for the PCB arms. You need about 145mm on the outer edge for the EzyBox and about 90mm for the PCB, not impossible by any means but the should both really have rolled edges, or a bit of thickness. If you asked me to make one I'd get a thinish chopping board and cut it out of that.