The image of the half mark is neat because the 0 in the date stamp circles the F completely!
You can also identify the type based on the serial number. The F is for Forbes lithograph. Forbes printed all the AMC marks except those printed by the Russians. The Russian printed notes do not have the F.
The serial numbers on Russian printed notes are also different. They will start with a dash (-) like the Forbes replacement notes. This is because the Russians were provided specimens made from replacement notes and assumed the dash was an integral part of the serial number. Forbes replacements will have low serial numbers (starting with a dash and at least two zeroes) and the Forbes F. The Russians also used six digit numbering wheels so the nine digit numbers were done with two separate wheels and there is usually a noticeable gap between the third and fourth digits (-12 345678) or they are not aligned properly or the space is narrower than the other spaces between the numbers. This is true for all except the Russian printed half mark note which does not show the gap in the serial number.
IN the pick catalog the listings are :
a. 9 digit with F (Forbes printed regular note)
b. 9 digit without F (Russian printed number in excess of 100000000)
c. 8 digit with dash with F (Forbes printed replacement - this is why it is priced so much more than the others)
d. 8 digit with dash without F (Russian printed number less than 100000000)
The Russians did not exceed 100000000 on the half mark note or the 1000 mark so there is no listing for 9 digits without F.