After looking at it again, I guess it's some type of LC resonant tank, with 2 1/2 bridges, and the gate drives being driven from the other side, and not some other source on the primary side.
But hey I got a 36V out model working, with values like I might find in a computer PSU gate drives.
I would think the H1 winding should be control Vcc for the TL494, but they do have it drawn incomplete, because pin12 is only connected to the supply cap. I would think D105 rectifies H1 for the IC, and the top of the 47uF C107 is local Vcc.