So I went to Half-ords and they dont do plus gas !. Not a wasted journey as I acquired a replacement tin of silicone lubricant (my reward for showing a stepson how to WALK to halfords). I might resort to taking the tailgate apart as it looks easier than the door trim

.
If the weather is nice I might do the very long walk past phoenix (where one can get rather large quantities of diff oil

) to a motor factors.
Is there another name for plus gas ?. I assume WD40 is a no-no down the keyhole ?. But I have found a spray can of brake and clutch cleaner in the step sons hoard of might be useful purchases - might that be solvent enough ?.