Echo Peter
Having recently replaced the dome on my 21 year old Ritchie and having dealt personally with Ritchie's parts department, Peter is right on this. Ritchie, a long time ago, used an alcolhol/water mix. They switched to odorless mineral spirits about 23 years ago. Do not confuse mineral oil with mineral spirits. Mineral oil thickens in the cold and mineral spirits does not. They have recently switched to a new filler, however, I don't remember what they called it as it didn't apply to my use.If you can identify the leaking area and you do have Ritchie, their parts are readily available, all you need is your model and serial number. Their phone number is 781 826 5131.By the way, I don't believe that I would be using olive oil, too thick.Luck with it!