Geoffrey is of course right when he says you shall always change shoes and cylinders on both sides at the same time.
But, breaks are very good on left side.
Even the right side works on one cylinder, even the shoes are good

and the drum looks perfect inside.
Maybe just remove the cylinder and see if I can get it to work better and then change it all during winter.
"The wheel cylinders should be replaced in pairs. Never do only one side: that's a fast way to put back pressure in the other side and have that leak. Wet shoes are ruined. Remember, no brake drums are available!"
So I ask for opinons here please.
Do a complete change ? Or try a quick and dirty ?