Percy does not have a conventional stern tube greaser, Tony Redshaw fitted an automatic greaser called the Greasomatic 96 (great name)
The link to the supplier is here Wymark
It seems quite simple and logical as well as useful for boaters like us who are not aboard all the time checking the stern gland. This cartridge is constantly under pressure so any demand for grease (the ones I have ordered have waterproof grease in them) is supplied. They can be set for up to 12 months use per cartridge, I think I'll go for 9 to start with. They have a clear body so you can see what grease is left.
Biggest endorsement is Tony is fitting one to his new boat.
I'll keep an eye on it of course but seems like a good solution to me.