Thanks Fish. Interesting the profile shows the cannon removed. Any take off or in flight photos of the 4 cannon and rockets? Since they removed the cannon on the rocket firing Hurri for the RAF I'm assuming it was performance and weight issues.
From what I can recall, the cannons where not removed on some planes and on others the 2 outboard 20mms where removed. I think this might have been a pilots preferance.
Some more information, I just found (will try to verify)
Sea Hurricane Mk.Is fell into three classes
Mk.Ia - catapult spools but no arrester hooks. These were used on the CAM ships.
Mk.Ib - catapult spools and arrester hooks. These were used on the fleet carriers such as Indomitable, Eagle and Victorious.
Mk.Ic - no catapult spools but with arrester hooks. These were for use on escort carriers. This last information comes from a BAe source, and I've not found supporting evidence of any such airfames. There have been statements that the designation was used for Mk.Is with four cannon, but despite claims that 100 of these were built and some used on Operation Pedestal, it seems that only one or two prototype examples were tested, and these reverted to standard armament because of the weight of the weaponry.
There were two classes of Sea Hurricane Mk.II - the Mk.IIb (including Mk.XIIb) with 12 303s and the Mk.IIc which had four cannon. This reflects RAF terminology. However, these aircraft were only used from escort carriers without accelerators. It is quite possible that they did not possess spools, but certainly looking at a Mk.Ib will not be of any assistance.