I've got small Landmann Offset smoker I don't want and I thought I'd offer it here before giving it away on Freecycle.
If you can collect it from the borough of Greenwich in London, it's yours.
It's not very great quality the steel is very thin. I modified it to work (slightly) better doing many of the things mentioned in this thread.
PM me if you are interested.
Here are some photos.
You can see the extra thermometers at grate level
The interior total grate area is 30cm x 54cm
Home made "tuning plates" (err. that's baking sheets to you and me!) and chimney extension (half a loaf tin!)
Baffle (more baking sheet perchance?)
Tried to seal the lid as best as I could with high temperature silicone sealant
Fire box with removable fire basket
The fire basket is the best thing about this, made by a friend who owns a construction company. When full, the smoker can burn for about 5 hours before needing more charcoal.
The air intake has been modified to take an Auberins blower,
But it's easy enough to remove and replace the original vent door
And you can have the cover too
The dimensions are 110cm long, 106cm high to top of chimney, 56cm wide to edge of shelf.
Just pm if you are interested and have the means to take it away.
PS it doesn't even have to be to a good home