@ aviate1138
The hut was non magnetic and vital to setting the bomb's heading correctly.
I assume that you are talking about a separate building to the "on their side skis" structures. These ski structures would not allow you to align the compass due to the fact they comprised a lot of steel reinforced concrete. The V1's would have to be taken outside, and well away from any steel to align them. Once the V1 had been hit sufficiently to align its magnetic field they would have to be used fairly quickly before the magnetic fields in the steel & iron of the V1 changed again.
Wooden mallets were used for a couple of reasons; no sparks and also less likely to fracture or deform the V1 casing.