Gring,

nice - another Tipo!

Retracts: This is a matter of personal preference but typically for trike setups, air or electric is the way to go as the setup is simpler. If you do go mechanical, then MK gear are nice but a little hard to get. And if you go with MK (or other mechanical), be sure to use two servos to simplify life for yourself. Frankly, I think the best all around solution for classic pattern trike designs is to go with Spring-Air or Robarts pneumatics unless you are trying to build a re-creation.

Servos: The HS-65HB is a great choice for throttle - fast, strong and precise. A great little servo even for reduced scale classic pattern models (like my Picorare - a 40" span Tipo! ).

For control surfaces on a 60 size model, I'd rather use Karbonite gears than metal. The latter are not needed and eventually can produce slop (steel not Ti). Hitec designed Karbonite gears for this reason. In terms of what brand and type there are many options for a classic. Again, personally, on a precision ship such as the Tipo, I'd rather use digitals or, if the pocketbook restricts this, I'd use coreless analogs. Coreless servos are very nice and center precisely. I'd use ~70 oz/in servos on aileron/elevator controls and something perhaps a little heftier on rudder. I'd setup the rudder with a P-P linkage.

I am actually doing exactly this on a GP glass Tipo. I'm using Kraft multicon gear on mine so I have a total of 6 servos in the model (+ 1 amp for the gear) with one being used specifically for steering. A picture of my radio install is shown below. In your case, if your fuse is made of wood, I'd install a steering servo (a flat one would do nicely or another 65HB) on the tank floor and use the space for the steering servo in my layout for the retract (pnemuatic) servo. Of course, you might need a larger plate (or a separate one) to mount the valve. An option would be to put the throttle and gear servos up front behind the tank plate and under the front wing mounting point. On wood fuses this is nice because you don't have a screw plate that gets in the way of the radio install. Finally, I strongly recommend that you install your elevator servo for linear output if you are going to use a forked pushrod. Other options would be dual rear mounted servos or to use an MK elevator bellcrank system. Both are nice but neither is classic. A Dave Brown arrow shaft pushrod is the honorable way of setting up the elevator linkage.

Hope this helps.

David.

P.S. I just read the end of your post and see you built one in the 80's - you can dismiss most of what I said above regarding layout - you probably have your own system.