Looking through the web to see any pictures or information on those parts. The GS2320D may do the trick, but checking that out I am thinking the diameter of that disc may be too wide (markins base is 5cm diameter) which will result int he legs not closing up when packed up. Also i am trying to find out if anyone has pictures of the GS2320D underside to see if it is flat or not or if the hole in the centre of it is big enuogh to feed the hook tube.
The kit you mentioned could be the solution but then i would be finding out if the hooktube length is the same as the current model I have, which makes it pointless to buy the whole kit hehe
I checked that the part "D1550.01" might be the solution as it is used on the GT1541T, but even then i'm not sure if that will fix my problem...
Oh i did try it without the centre column with the gitzo head, but I guess i am one of those guys that will be sellign the gitzo head and looking for the same solution but with the markins head =\ =\