STY
"Doubling of the frame at the comers: the right side at the bottom, the left side at the top, the top at the right and the bottom at the left; of both numerals, the bottom of the left box, the vertical, bottom and inner lines of the right box, and ONE CENT"
STY
The stamp illustrated would (just barely)seem to match Marler's description. The marks in CENT are barely discernable; Marler seems to have usually ignored such minor details. However, the rest of his description, including Type R4 seems to match very nicely. Thanks, Simon!