The R27c double transfer at bottom is fairly common, considerably more common than the DT at top or DT at left and right. It exists in numerous plate positions varying considerably in the amount of doubling. I have a block of 10 where the top 5 stamps all have double transfers.
What is nice about the example below is that in addition to being one of the more dramatic positions, exhibiting additional considerable doubling in FIVE at left (most positions do not), but also the stamp has a very crisp sharply struck impression, making the doubling that much clearer.
The image below is 1600dpi, so you may need to click on it to open it at full size.
