1) Engine oil what grade oil should i be using and i assume due to the vehicles age i should be using a mineral oil as oposed to a semi synthetic oil
2) Spark plugs i cant seem to find the NGK equivalent for the plugs fitted to my engine and as the places i shop for parts only stock NGK does anyone know the answer to this ?
3) GEarbox oil... what type of oil should i put in ? i would think EP90 due to its age however i may be wrong on this and also really silly question time where do you fill the gear box oil at ? and where is the level indicator i assume its similar to other vehicles of its age with a inspection hole that you open and when it floods out of there its full ?
4) Fuel line what size fuel line should be fitted to my camper as i have found the parts of fuel line to the expansion/balance tanks is perished and in need of replacement and some of the fuel line at the back end looks to be in a bad way so i want to replace the lot and resolve that issue and give myself peace of mind

5) Automatic choke ? how does this system work on these early air cooled models ? as mine seems to tick over very high when the engine is warm and i think its running a touch on the rich side due to a sticky mechanism or something ? i know i have the solex twin carb setup and apparently they were balanced and set up just before i picked the vehicle up by a professional garage however with some of the little things i have found that are not as how i was informed they were i kind of doubt this... im capable of balancing carbs myself and sorting them out tho as i have a lot of experience with 2/4 cyl motorbikes

I apologise for the barage of questions in my defence the vehicle is as old as me and i have no experience of VW aircooleds or T25's i am mechanically minded and competent with a spanner and i do own a manual for it but its about as much use as a chocolate fire guard (as with all haynes manuals) and would like to make a start on the little niggly jobs with a bit more info and knowledge than i have at the moment

Many thanks in advance
Dave