Sambar problems

[tappingt]

Rite, iam new to all this to be honest. my friend has a sambar (vw lookalike) so its not a truck but a van. I serviced it yesterday but noticed a few problems, and wondered if you could help at all?
Their is a bad oil leak coming from the top of the oil filter housing was there before i started the service and the leak is def not coming from the filter itself? it is leaking from a seal at the bottom of the timing case. does anyone know how easy the oil filter housing is to remove to reseal the leak?
Secondaly the combi switch is faulty and rarely works, i was wondering if this was common too? e.g. the contacts corroding etc?
your help would be much appreciated.

Its a 700cc supercharged lump not sure of the engine number, model of car etc but i cant imagine they're all too different.

[Rural]

[...]Secondaly the combi switch is faulty and rarely works, i was wondering if this was common too? e.g. the contacts corroding etc? [...]

If by combi switch, you mean the head- and signal-light switch, my impression is that this is common. At least, it happened to me. In my case, the contacts are corroded and are getting better with use. However, the right thing to do is to disassemble the steering wheel and clean the switch contacts as in this excellent post (http://www.minitrucktalk.com/showpost.php?p=21706&postcount=10).