Viet Nam: Full sheet of airmail labels

Here is a nice, complete sheet of 40 airmail labels from Viet Nam!!!

Year: approx.1970, Ungummed. Günter Mair's catalogue no: - VTN-A-5a, rouletted, sheets of 40(5x8)
"May Bay": 28mm; "Par AVion": 28mm, reference: "H-32", black/light grey-blue, 3***