Upon the presentation for recording of any instrument which is exempt by law from the payment of the tax provided for in this chapter, the town clerk shall stamp in bold letters on the face of such instrument the following legend:
"No Conveyance Tax collected.
....
Town Clerk of ....",
and thereafter such instrument shall be recorded by said town clerk.
Conn. Gen. Stat. § 12-496
(1967, P.A. 693, S. 3.)