Flask head assistance

[hhughh]

I'm posting this here and in the Darksider's Den, hoping someone one place or the other can help.

Several years ago, I purchased a flask---Italien repro of the Colt Navy flask, and a couple of weeks ago the valve, release, etc. broke.  I ordered a replacement from Dixie, and it arrived today.  However, it's not drilled or tapped for the little screws that secure it.  I'm going to call Dixie tomorrow to make sure this is proper and not an "oversight".  But, preparing for the worst, does anyone know the drill/tap size for these holes so I can mount the head?

Thanks to all,
Hugh