If you google "Bullseye Putter History" you will get good information on this putter introduced in the mid 1940's and acquired by Acushnet (Titleist) in 1962.
Here is some model information:

STD - Standard
OS - Old Standard
O-Set - Offset
OR - Original
LB - Light Blade
HB - Heavy Blade
LAF - LaFemme
JR - Junior
FL - Flange
LHFL - Left Handed Flange
LFL - Heel Shafted Flange
WFL - Wide Flange
WFL-O - Wide Flange Offset
HSF - Heel Shafted Flange
HSF-II - Heel Shafted Flange II
ML - Mallet
MLO - Mallet Offset
MLI - Mallet I

Length:

4 - 34"
5 - 35"
6 - 36"
"LaFemme" - 34"

Lie:

M - Medium
U - Upright
F - Flat

Grip:

P - Paddle
S - Standard
C - Cord
#4 curryj
Here is a listing of the original designs.
Original: Medium weight, rounded toe, flat top. For right or left handers.
Old Standard: Medium weight with square toe and top blade. Sight line
Standard: Medium weight with rounded toe and top.
Light Blade: Like Old Standard but lighter, narrower.
Heavy Blade: Like Old Standard but with heavier, wider blade.
Bulls Eye Junior: Standard blade. 30" shaft. Scaled-down grip dimensions.
Heel Shafted Flange: Medium-heavy weight. Offset hosel. Sweet spot slot for improved feel and alignment.
Heel Shaft Flange II: Like the Heel Shafted Flange but without the Offset.
Wide Flange: Heavy, wide flange for low concentration of weight. Sweet spot slot. Idea. for large or slower greens.
Wide Flange Offset: Same as Wide Flange but offset.
Flange: Medium weight, slightly offset. Single sweet spot sight line.
LaFemme: Light weight for the woman golfer. Rounded toe, top and flange.
Left Handed Flange: Like the Flange but for the one out of every dozen golfers who plays left-handed.