Re: to buy a 146 or not
As a pointer ref the gearbox oil, I dont think mine has been changed by the previous owner and I hadn't changed it until last month (so that's about 5 years).
When it was changed, it came out as clean as a whistle and virually no iron filings.
I think it took a little over 2 litres and use fully synth.
Maintenance wise, as you have already pointed out, check the oil every week and check the relays in front (and to the side if it's a Mk1) of the battery box as the relays ans wiring often rot. Give them a thorogh check and it they look grubby, remove clean and spray with contact cleaner.
Front tyres wear on the inner edges if the tracking is even slightly out, so spend £20 and it it done.
Rear washer motors seize easily as the shafts dry up.
Also, I just had mt brake fluid checked and it was 6% moisture, had it changed and it made bot all difference to the stopping power.
Also, I have found that franchised dealerships are extortionate and are to be avoided for routine servicing etc. Anything I have needed doing, I have bought the parts myself (local motor factor - much cheaper than on line shops, such as Shop4parts who are v expensive).
Other than that, common sense applies - can we have some pics of your car please?