Servicing Gibb winches

[ghostlymoron]

I have two Gibb self tailing winches on my boat which are a trifle stiff to operate. The model is 28STA single speed. I am perplexed over how to dismantle them as they do not have a screw head inside as I have found on other makes.
Any suggestions as to how I access their inner parts?

 

[macd]

Don't know that model, but some Gibbs have an inside circlip, possibly under a steel cover, at the top of the winch-handle slot. Should you need pawl springs, I found that Lewmar springs fitted an old Gibb 40.