Replacement door locks ?

[MIG Wielder]

After just 40 years (!) my drivers door lock has worn , so much so that locking & unlocking is a bit iffy. It looks like a lot of free-play in the lock itself.
I found these ...
http://www.rimmerbros.co.uk/Item--i-GRID008271

Does anyone have any experience of these please ? They look the same style as on the Halfords steering wheel lock with a round key.
It looks like there is no external shield where the key is inserted to stop water getting in. So it may be difficult to operate in frosty weather. Like today.
Can you get spare "keys" cut ?
I can see they are good to defeat the "stick-a-screwdriver-in-and turn-it- to break the lock" brigade.
What is the retaining mechanism ?
Do they fit in the same hole in the outer door skin ?
Thanks very much,
Tony.

[Bumpa]

I have had these key locks on my MGB V8 for the last seven years and they have been fine. They go through the original hole and are fixed with a nut at the back, so are nice and firmly fixed. The fixing nut is the coppery looking thing behind the lock flange in Rimmer's picture. On the MGB the standard locks are fitted with a sprung clip which allows the lock to pivot as it wears and becomes loose. They came with spare keys and I haven't needed to try and find any spares. The only slight drawback is that it is a bit of a fiddle getting the key in the hole the right way up when it is dark. I feel for the little nib on the key because that needs to be at the top. I haven't had any issues with water in the lock. I give them a tiny spray with 3 in 1 occasionally and that's that.

On a Dolomite with those door sill buttons, that would surely be the weakest point in terms of resisting entry. Why fiddle with the lock when you can hook the buttons with a bit of bent wire!

[MIG Wielder]

Hi Mike, Thanks very much for your most comprehensive reply. Yup, I think I shall give these a try.
Cheers for now,
Tony.

[Howard81]

Worth taking the lock apart to see what is worn. It might just be the lock outer - they tend to groove over time. You can swap your existing barrel in to another outer.

Either that or swap it to the other side..