PVC foam sheets of approx 6mm are very quick an easy to form by hand into compound shapes on a rough jig made of plywood and stiff wire.
3/16 stainless steel rod works well to make good curves naturally. Plywood ribs across fairing, rods running chordwise. Leave rods long.
Wire rods to ribs as ...

A dipole is normally straight not a Y shape.
Calculate length for speed of light, less 5 percent for copper.
Dipole normally total length of half a wavelength.
To increase bandwidth use thick legs or several wires which can be thin to save weight.
Spread wires approx 2 inches apart and bring ...

a wax cylinder and a needle would probably work quite well or try drawing a circle on a piece of paper
to reduce vibration just cut off mixture to engine

most/ all Lycomings can be fitted with a wobbly prop but the crankcase may need splitting to insert the necessary gear unless was fitted previously, see boss near front of engine

dalton computer/whiz wheel works well and easy to use
need to record altitude and pressure setting of altimeter, OAT, IAS and of course check ASI by your preferred method
need a still day to keep a/c straight and level for quite a long time
ideally use measured mile on ground but not practical for ...

aero engines have considerably more blow-by than modern car engines so combustion products acid etc probably reach the oil to a greater extent requiring more frequent changes.
personally I prefer S100 if the machine is often unused for several weeks
filter screens have worked well for many years I ...

one inch temperfoam is very comfortable on a suitably curved base and not particularly expensive

fuel should be clean
tanks should be clean
filters should be clean
just do the necessary maintenance
very fine filters pretty pointless except for injected engines
fine filters that cannot be checked just have to be regularly changed

yes fit ferrites on power wire to strobe just inside strobe box, can fit just outside but not as good, test on ground etc.