EFO 1942 surcharge A

Top stamps have deleting bars covering the small COMMONWEALTH overprint, bottom stamps don't.

Block of six 5-centavo surcharge of 1942 on 6-centavo Filipina allegory stamps of 1935 overprinted in 1939 with small COMMONWEALTH in two lines.

1948: Rizal O.B. overprint

On December 30, 1948 another official stamp was released, this time an OB overprint on the Rizal 2c green definitive. This was the last issue for 1948.

Printing quantity: 12,999,100
Overprint printing by the Philippine Bureau of Printing
Perforation measurement: 12
Unwatermarked paper

The quantity printed was reduced by a later surcharge.

Overprint freaks:
Shifted and slanted upward (reading B.O. instead of O.B.)

[Data taken from various sources.]

1948-49: O.B. overprints

The first official stamps of the Republic era were five definitives of 1947 overprinted O.B. (for Official Business) issued on different dates:

May 1, 1948 (4c and 10c)
May 28, 1948 (16c)
January 23, 1949 (50c)
July 4, 1949 (20c)

The overprinting was done by the Philippine Bureau of Printing for the 4c, 16c and 50c and both the Philippine Bureau of Printing and the American Bank Note Company for the 10c and 20c.

Quantities printed:
4c (14,998,500)
10c (9,499,500)
16c (999,898)
20c (4,500,000)
50c (400,000)

A total of 787,879 of the 16c was withdrawn on July 26, 1950.

There are two measurements of the O.B. for the 10c:
13mm Manila printing
12-1/2mm New York printing

There are two measurements of the O.B. for the 20c:
13-1/2mm Manila printing
13mm New York printing

Errors:
4c overprint inverted, overprint doubled

Shifted overprints:
4c leftward, rightward (the extreme is B.O. instead of O.B.)
10c leftward, rightward, downward
16c leftward
20c rightward

Varieties:
10c small period after O

[Data taken from various sources.]

1946: 50th Anniversary of Martyrdom of Rizal issue

The only other Republic stamp issued in 1946 was for the 50th anniversary of the Martyrdom of Dr. Jose Rizal on December 30. This was an overprint of a Commonwealth definitive issued earlier in 1946 before the Proclamation of Independence issue.

Denomination: 2 centavos sepia (with black overprint)
Quantity printed: 1,500,000
Printing of base stamp by rotary press
Printers: US Bureau of Engraving and Printing (overprint by the Philippine Bureau of Printing)
Perforation measurement: 11x10-1/2
Unwatermarked paper

Shifted overprints (in different degrees):
downward
downward and to the right
downward and to the left
upward
upward and to the left
leftward
rightward

One source says forgeries of the overprint exist but I don't know what the differences are from the genuine overprint.

[Data taken from various sources.]

1946 Rizal Martyrdom

The 50th anniversary of the Martyrdom of Dr. Jose Rizal was commemorated on December 30, 1946 by overprinting an earlier Rizal definitive.

Denomination: 
2 centavos sepia (with black overprint)

Quantity printed: 1,500,000
Printing method:  Rotary press (base stamp)
Printers: US Bureau of Engraving and Printing (overprinted by the Philippine Bureau of Printing)
Perforation: 11x10 1/2
Unwatermarked

The stamp is common.

For the first day cover, the Manila Post Office used a round, borderless handstamped cachet (top photo), but collectors were allowed to use their design (bottom photo) in addition to its own.

Varieties to look for: Shifted overprints.