Offenhauser manifold fittings & pipes!!

[Jono FD3]

Hi guys, not going to be long now before I fit the engine in to the truck, but need to ask a few questions....... basicaly my offy manifold hasn't got a take off for the servo vaccum, but there is a large nipple blocked off on the holly base plate, so I presume I can use this for the servo?
And the main one is this.... there are 2 threads in the water way to the left of the thermostat (one on the virtical plane and one on the horizontal) I take it that the previous owner must have cut another hole for an auxilary gauge?

Jono