How long roughly does it take for a new kennel name to be allocated?

Once the KC accept it, you have to wait for any objections.  Mine was accepted in April years ago, although the KC told me not to use it or have anything printed with the affix, until cleared.  It took until July.

Mine was granted within 2 weeks (I checked my kc account online asit was added there first) received the letter about 3 weeks after application.

I applied in June and had to wait until august for it to be confirmed 100%.

Mine, from application to receiving the certificate took 3 weeks - back in January :-)

Your affix will appear in the Kennel Gazette & any objections have to be lodged within 4 weeks of the publication of KG...