Mode 1 and Mode 2 are both about 57 Hz.

For a 2200 kg mass, it would be possible to do a static structural analysis to compute the stiffness of one foot and do a hand calculation of what the first natural frequency must be from the mass and equivalent spring rate of four feet.

The mesh has 1.3 million nodes and I got the first 6 modes out in 19 minutes on 9 cores using the PCG solver. I spent about 20 minutes doing geometry cleanup to get it down to this small model.