These are Penny Reds

although as you see these are an unusual shade of red.
The ink of the day and the fact these are 150+ years old though goes some way to explaining it.
The ones with on letters in the bottom position are earlier varieties. The ones with all four letters should have plate information printed in the left and righ borders.
There have been a few post recently regarding this which you might want to search for.
Theoretically each plate had an equal range of letters -
AA AB AC AD AE AF AG AH AI AJ AK AL
BA BB BC BD BE BF BG BH BI BJ BK BL etc.
so HH shouldn't have a premium but sometimes the double letters do.
The site
http://pennystars.com/ is a good place to start.