LOL Seal.I did the same thing. Although my plates had the BS mark and a postcode (of sorts)..it said Dublin on them lol.
Got pulled by the cops, had a nice(?) discussion with them about the legality and they were adamant they were illegal for several Bullsh!t reasons and maybe one valid reason (the dublin marking).
They told me to get them changed and off I went. I ended up writing to the DVLA and Tayside Police to find out what was/wasn't legal.
It seems (and this is just my opinion from research) is that if you want to be sure you are road legal, the safest bet is Dubmeister since they are on the DoT's list of registered plate makers (unlike the majority of ebay or other website sellers). But no doubt if you find a jobsworth cop, you'll still get hassle even about the Dubmeister's. It just depends how much of a PITA he/she wants to be.