RE: George Miller F-4 Build - also, welcome George!
I will give you suggestions, but you probably will not like them.
Decide right off what you are going to do with this aircraft. Then build it accordingly. If you are planing on going all out scale and entering it in competition, then you can figure you are going to wind up in the neighborhood of around twenty pounds at least. Mine weighed 21 pounds. Most others I have knowledge of weigh a lot more than that. And 21 pounds is just about at the limit for this aircraft to be a good flying aircraft.
If that isn't what you are building it for, then don't build it that way. LOL If you go look at the site that has my video catalog you will see two A-10's there. The second one was for a shop in Singapore, and was only for sport flying. It weighed only 16 pounds if I remember correctly. Now it was still total scale, but just didn't have a bunch of extra added detail and weight, was fiberglass fuselage and foam wings.
1. I believe the plans show my retract system I used and designed. Although it worked very well, I would go to Spring Air retracts all around. I know there are a couple companies that make custom scale gear for this A-10, but I believe they all weigh a ton.
2. If you are not building it for all out scale, it does not need those flaps. So save yourself some time and weight by not building them. This aircraft has one hell of a wing and airfoil on it. The flaps are only needed for show. Half the time I didn't even use then when flying my competition model.
3. Build the fuselage including the engine housings all as one piece and forget about hatching for the engine access. I think there are still companies that make the front and back engine housing pieces out of fiberglass. Get those and glue them on. Don't use them for the finish model, because I believe they are made out of epoxy and weigh a ton. Now give this whole than a very cheap but smooth finish.
4. You now have a plug. Take it and do a "One Off" out of fiberglass right off the plug using two layers of 6 ounce cloth, reinforcement in the strategic areas, and with Isophelic resin. In the end you will discover that not only is it a whole lot lighter, but it is stronger and also is not full of bulkheads and stringers. You won't have to eliminate the wood grain of the wood fuse or anything like that.
5. Go electric. Use Lander Fans. This allows you to save the weight of the glow engines, tune pipes sticking out the short housings, the placement of all the heavy fuel in a tank between the engines, no fooling with needle valves, fans unloading in the air and winding up too lean, or one engine failing. All this weight back here is not good. And you are definitely going to need nose weight no matter how you build this aircraft. So here you are with a aircraft with less weight behind CG and Batteries, ESC's, And a BEC that can be in the nose to balance the aircraft. Time to get with the new way of doing things.
6. The lighter and simpler you make this aircraft the more fun you will have with it. Never stop thinking of ways to save weight when building any model.
Well hows that for starters?