using small cars for weddings and special occasions?
a member of the fiat500 club has done it and the car looked brilliant, no doubt there may be a bit of red tape to sort but there wont be many fiat 126's doing it!
Most classic car insurance policies will mention this explicitly, either to include it or to exclude it, and also to specify whether it is done as a commercial activity or not. Check your policy wording. Generally it's included IME provided there is no financial return. So if you do offer it for beer tokens, make sure it's strictly cash and there is no tell tale audit trail of invoices, emails or text messages that an insurance firm would seize upon as a get-out clause.
Any arrangements for any form of reimbursement are generally best to be non-monetary - ie do a favour for a friend, he can do you a favour in return some other time.
Be aware that most wedding clients will want the reassurance of a back-up car being available if the weather is bad (no room in a 126 for large brollies) or if the car breaks down. Because of the time constraints, the back-up car usually has to be literally on stand-by with the engine running (well, almost!).
An alternative to the complete DIY approach is to get registered with a wedding car agency, where you and a load of other classic car owners are on the books of a central agency that handles bookings, insurance and PAYMENT!! The down side is that these places generally have a fleet of SERIOUS classics, like 1908 de Dions and Rollers to make your mouth water. I once tried this with my now-sold Jag XJ Sport, full cream leather, the works... they weren't interested... too 'common'... so don't get your hopes up that there will be much demand for a humble 126.
You know she's gorgeous, and *I* know she's gorgeous, but to most of the brides to be, it's just a funny odd little car she wouldn't be seen dead in. A 126 does *not* have the cache of a 500.