The base is flat. Central hole 3/8" 16tpi, plus two holes M8 either side, 35mm apart, and another pair of holes M8 70mm apart.
It fits fine on my ancient SLIK Master tripod with a 3/8" screw.
Pretty sure it would bolt onto this tripod
https://www.bintel.com.au/product/sk...SABEgLOcfD_BwE