Not embossed edges wt1, "saw tooth" rouletted serrated perforations
1945 PRO MONTEPIO
(For the benefit fund collected by a society for its members)
GALVEZ page 392 lists these and states that they exist overprinted
Sawtooth (serrated) rouletted.
"Sin Valor Postal" =without postal value
Gibbons stamp monthly
This should be the complete basic set
apart from the overprints.