Possibly 223/4 depending how its measured. I dated it at 1946 from the serial number and a bit of online nerding. Accles & Pollock Cro-Mo, a competitor to 531 in those days. Frame + forks are true, I had them checked at Brian Rourkes shop. The forks are fully chromed, the rear triangle partly.
Lots of defects to the finish but so nice to find an interesting one that hasnt been messed about with. Its a race frame but no reason why it couldnt be toured on, too light for full camping load but can fit mudguards. I have about 8 bikes. Just got to make some room. The item "Hobbs of Barbican Criterium vintage 1946 Frame & forks, lugless, fillet brazed" is in sale since Monday, September 24, 2018.
This item is in the category "Sporting Goods\Cycling\Bike Frames". The seller is "rightinthegroove" and is located in Hitchin. This item can be shipped to United Kingdom.