The details on the speakers are:
Celestion
G12-30
Impedance 15 Ohms
ROLA CELESTION LTD
Ditton Works
Foxhall Road
Ipswich Suffolk
England
HN22
T3319
Insp 11
This following photo is not my speakers, but is exactly the same as those I have:

Any idea what year ... original owners said 1970 ... but I always thought greenback celestions were then ... I am thinking more 1980s.
Can anyone decode the info above ?
30 watts ?