Stuck on a Few!
1. 2=C for NZK
2. 5=L in a MS
3. 9=SR
4. 30= P in an OHC
5. 40= O in a Q
6. 1= IM of OD
7. 10=TF,TTT
8. 3=AI
9. 9=BRWIHT
10. 0=SBC in H
An old half crown was 2/6 which means 2 and a half shillings. There were 12 pence in an old shilling so 2/6 would be (2x12) +6=30. So weecalf IMO is correct.
Puternut - weecalf is correct
An old half crown was worth 2s and 6d (that's 24 + 6 = 30 'old' pennies).
and you are also correct that the quivalent in new pence is 12½p.