Re: Sinhalese mss.

If you can afford it,

   (1) Go to Sri Lanka,
   (2) Bring your own digital camera.

You are correct that arranging for a copy to be made and sent from old
Ceylon is "improbable" at best.

Probably you would be well advised to check against the possibility of
dust-covered inter-university sub-agreement that requires the second
party to provide you with a copy of works in storage under conditions
X, Y, & Z --many universities have rarely-invoked special priviledges
of this kind ("Dharmashastra" sub-clauses --precisely to protect
people in your situation).

E.M.