Thanks David! This is a good reference for when I I'd part-perfs.
@PhilatelistMag20 The 3/16 inch is only valid on just R27b! I can't find my notes for other part perf. measurements!
Dated April 22 1863 (I think) Nice strip of 5. You can use this image between stamps at 3/16", for this issue
re: R27b Strip of 5