The examples below are both PP11 a 1d. rose-red (SG 40 or C10) plates unknown with the J. & C. Boyd & Co. type 5 underprint.
Note. There is a marked variation in shade between these two underprints. The first shows a fairly normal red underprint while the second a much darker brown-red. This appears to be quite common for the unofficial J. & C. Boyd & Co. underprint type 5.