Fake Nichicon PS series?

[s675]

3 or 4 years ago I purchased a TDA7293 amplifier board from eBay.

I have never used it, but I looked at at and noticed that the large filter caps are ostensibly Nichicon PS(M) 2200uf 50v. They measure around 16x26mm (15x25mm?).

I was surprised that a cheap board would come with capacitors like these. The small ones on the rest of the board are various cheap brands.

This is more curiosity than anything else, but I wondered whether they are fake. In particular I noticed the difference in heat-shrink at the top, and the slightly different looking vents. Is this disparity in appearance normal?