[morzh]

Wire gauge is only critical in case it needs to take the current. In case of your tubes AWG38 can. Although I think AWG34 or 36 is better.

The length of the coil that is connected to tuning cap (usually in parallel) is somewhat critical, as the length affects the inductance and the latter affects the frequency. Whenever you see a coil that is not coupled with a cap, the length is not critical and only number of turns is.

Now about the direction: you do need to observe the direction of winding if you have an oscillator: the coil should be wound in the same direction and the start and end wires should match too. Or the oscillator won't oscillate.