Your connections are not correct.
On page 39, we provide instructions to test the outputs of the board, which are not the terminals on the front of the board.
On the following two pages, the instructions are to connect the green twisted wires to +reg and -reg on each side of the board.
The "DC" connections on the front of the board are used when this board is installed as an upgrade in the Stereomour II.
Thank you for taking the time to stop by and ask about this, as you have it wired now, both 300B filaments would be loading down one side of that regulator board and one transformer winding. Something would get really hot eventually and fail!