If it helps see here:Link
Part number 76-2514
Also listed at Baxters: link
Showing it as a 2BA screw, as i say you can use anything here, and an Allen screw might be best (2BA aka 3/16 BSF).
As stated earlier these are not pillar bolts, pillar bolts are used on the unit singles so that the inspection cover can mount off the same screws.... The Unit twin is different and 2x counter sunk 2BA screws are used to hold the points inspection cover onto the outer timing case.