I do see your point with the hatch limiting usable space. I think it is a personal thing as well, I just do not like the idea of removing prop shafts, linkages to access the inside of the WTC. I want to be able to leave hatches open in storage to prevent dampness inside etc....
With regard to the tank, I can possibly make parts and get access to a lathe, but I intend to use mainly pre-made parts and do not think it will be necessary. I have a oil pump similar to this type of thing;http://www.ebay.co.uk/itm/Oil-Fluid-Suc ... 1c3016f2cf
It is smaller and stumpyer than that one and a perfect fit for the IX. On the one I have the centre pin is threaded on one end and bolted through the rubber piston seal so I intend to unbolt that and substitute a fully threaded bar. For the gear box I will fabricate the housing out of brass plate and use the old metal mecanno gears. I will tap out one of the gears to fit the threaded bar and operate the tank. For now it will be limit switches for operation. Eventually I would like proportional control but that is another story. The piston is basically pre-made. I hope it will be a nice easy way to make a piston tank, but nothing ever goes to plan!
I am debating whether to use full size servos or mini ones. That will also effect my decision on the wtc.
I was not aware you could join. What do you get access to for the fee?