Head Identification

[Tony Press]

I have a spare cast iron head with the following cast numbers,  single bolt water outlet.  What sort of engine was it from?  
Can anyone identify it please

Bob

3  11  8

1A 670

{  AF  }   ignore the curly brackets
{   2   }
{   T   }

3rd November 1928 ?

I thought a '28 had petrol tap primers in them??

The head 1A 670 (Part No. BC 82 ) was introduced in 1933 (with slightly raised compression), so is the date number actually 8 11 3 - 8th November 1933 ?

The earlier low compression head with tap primer plug holes I believe was 1A 684 (Part No BC 28) - I can't find any listing for a later 'intermediate' low compression head without primer holes used before the 1A 670, but I am sure there is one.

The later 'high compression head of 1936 is 1A 911 with the two hole water connection.