One of the most challenging issues on collecting perforation and watermark varieties is the stamp issue of
Quials and Partridges released on January 22, 2001. I still have not been able to figure out how many types of perforation and watermark for each of the three denominations. SG catalogue does not seem to be helpful as it is still in the middle of figuring out the actual number of varieties. I am listing below those perforation and watermark varieties that possessed by me (I think I have spare copies for these varieties). I am very happy to exchange with anyone for those varieties not in my collection.
in my collection (30 sen):
P13.75 sideway down watermark
P13.75 no watermark
P14.25 no watermark
in my collection (50 sen):
P13.75 sideway down watermark
P13.75 no watermark
P14.25 no watermark
in my collection (RM1):
P13.75 no watermark
P14.25 no watermark