Despite the lack of protection during transit, the base of the block was in perfect condition. Using a sheet of glass and water I was able to determine that surface of the base was very flat with no imperfections.
From the pictures above you can see that the base has been lapped to a semi-reflective finish. There is an ongoing debate whether lapping to a mirror finish actually produces any noticeable increase in performance, but in my opinion the finish above should be more than good enough to get optimal results.
On disassembling the block, I was rather disappointed to see shavings of copper lurking between the pin array on the base. Also, the insertion of the barbs seemed to cause small strips of delrin to fall inside the block. This is quite worrying as particles of plastic and copper could cause damage to some water pumps.
As you can see above, the internal base of the block was rather dirty and managed to turn one of my cleaning cloths a dark shade of brown. I strongly suggest disassembling the MP-05 and giving it a thorough clean before placing it in your water loop.