Here are  six Dollar stamps of the United States 

you have a -

1973 O`Neil $1 which is clean on the front no sign of any cancel mark plus the back is clean too

1986 Hopkins is used with obvious cancel 

1986 Bryans 3x $2  two of the 3 stamps are clean with no signs of any cancel mark plus the backs are clean , no sign of any gum and the third is used with cancel marks

1989 Revel $1 also used with a very light cancel mark 

so six stamps in total

 

I have uploaded a couple of data sheets from a stamp I.D data base for two of these type of stamps