Here are a few modern $1.00 FRN (Federal Reserve Notes) that you might want to look for.

1)1981-A $1.00 FRN w/signatures of
Ortega / Regan .Dallas FR. letter K with Star star = Star note . in Cu $
30.00 and Ch. CU $
75.002)Series of 1988 $1.00 FRN w/ signatures of
Ortega / Brady from the Atlanta FR. with Star and and sheet Fed check letter and number That would look like this --(
G195 )This would be located on the obverse to the right about a half inch from the right edge and about an inch from thr bottom edge. This note in Cu =
$175.00 and in Ch.CU = $
275.00.3)Series of 1988-A $1.00 FRN w/ Signatures of
Vallalpando / Brady.Some of these were sheet fed like the above example. but a few were printed on a Web Press. These are the notes you are looking for . The key to recognizing these notes would be instead of (having a face check letter and number combination
**F124** for example. They only have a number like the number (
4 ). Collect any of these you can. 4 Fedral Reserve Branches are worth only
$5.00 in Cu but New york w/ the letter(B) is worth
$250.00 in Vf condition and
$1200.00 in Ch.CU.. The next big one is Atlanta Letter ( F ),and has to be a Star note, is worth $
450.00 in VF and
$900.00 in Ch.CU Chicago letter G is worth
$15.00 in Vf and
$100.00 in Ch.CU. The number would be locate din the same obverse position as mentioned before , and there is a back check number that is to the right of Trust. Happy hunting any questions ask away. I will try to help if I can.