I agree with Happy Blue above.

There WILL be rust in the petrol tank - that means if you put petrol in it and the fuel pump works, teh fuel filter will block with rust and you may clog up the injectors.

ALL the rubber components will have to be replaced. The cooling system will need to be cleaned out.The braking sytem will need to be stripped and rebuilt.

You need a mechanic with prctical experience of these cars, who knows what will need doing and where to acquire spares.

This will NOT be cheap... £10,000s +

The car when restored will be worth well into the £100k ++ range depnding upon its history. NOT a car to be driven without great care..

And not cheap to insure either.

You will need a locked and alarmed garage as it could be a thief magnet..

A lovely car to own, but I suspect a money-pit. Depends if its been dry stored in a rodent free environment and why was it laid up in the first place?

These rust just like any other car of that age.

As others have suggested, unless you've got bottomless pockets, walk away.

The best option may be for it to be auctioned as it is.

Actually, I know just the people for this. O'keefe coach trimming services in Warlingham, Surrey. They specialise in restoring these old Mercs. I used to go to a business in the same building as them and remember seeing a Gullwing in there at the time.

Might be worth a phone call and a chat, they should be able to give you a ball park figure of what it might cost to get it on the road.

Thanks I'll take a look. I've had the car moved on a low loader handbrake wasn't seized it was winched on to the back of the truck and moved to its new location. I'm going to phone around and get a few quotes and then we will decide weather to keep or sell as is.

From wikipedia

"Today, the 300 SL with its gull wing doors, technological firsts, and low production numbers is considered one of the most collectible Mercedes-Benz models, with prices generally in the US$1,000,000–2,500,000 range. [6] Sports Car International magazine ranked the 300 SL as the number 5 sports car of all time."

The OP needs to take great care of it. Its worth its weight in gold. I just hate to think what IHT implication may be, you may be forced to sell it just to pay the tax man. Good luck!

While it's doubtless expensive to put back on the road - and keep roadworthy, I always like to see classics like this with a long history in one family, rather than just the latest bling for some overpaid 'sleb (or similar).
I would also like to hear what you decide.

.....but I'd have the engine, transmission and differential rebuilt by a specialist.

Why? If it's been well looked after during a mere 20yrs on the road the mechanicals should be in near perfect condition unless the mileage is unduly high. I would just pour a little thin oil into each cylinder, turn it over a few times and then pressure test it in case the head gasket has corroded.

If it works, don't mend it!

IF the car is original, then you may be betetr off doing minimal restoration.

An original car in excellent bodily condition with good mechanics is far more appealing to many collectors than a restored one.

I've got the car running changed all the filters sparkplugs ect overhauled the entire breaking system, cooling system and suspension . Cleaned the fuel system and new tyres all round, gearbox oil flushed as well.

All I've to do now is get ithe MOT'd.

It runs beautifully and on the private road where the lockup is it drove exceptionally well for a car of its age. Thanks for advice from everyone.

The car has been off the road since 1982 so over 34 yeas old. They didn't look like that had seen much wear but I didn't want to risk the car on rubber that old.

The car passed it's MOT without a single advisory but I'm thinking to maybe keep it off the road until spring next year.