It appears that the bottom and right were cut using pinking shears. It is not a roulette.
Agreed. I'm only aware of two examples of R5a privately rouletted. One is Philatelic Foundation certificate #510290:http://pfsearch.org/pfsearch/pf_grd...lledfrom=lkp
(I cannot link the image here.)
The other is in my collection. Tied to piece from an attributed entity (Samuel Dexter Hastings, state treasurer of Wisconsin).