Basically the difference is not of the year of manufacturing. It all depends on the material used in these models. The chassis is the same. And space you can always manage as per your planning of seat adjustment, the rear seats parallel to front ones or side ways at the back, height etc etc. Also the soft top has some advantage of the folding front screen.
In my opinion, in general, the steel used in an 82 model Japanese sj 410 is far superior than that of a 2007 potohar. You keep a new potohar in open without being used for a year or so, and it will get rust everywhere.
Than talking in detail about both these models/ brands, a japanese sj 410 or may be a late 80 model jimny sierra has the following things which even the 2007 potohar lacks.
- power steering
- survo brakes.
- front discs.
- balance rod at front
- 5 speed gear.
- EFI turbo engine
- RPM meter.
- foldable front screen/ soft top. (which in potohar came only till late 80's)
Apart from these there are too many other things like the japanese leaf springs, the rims are of very good quality, the adjustable front shocks (which i have in my jimny), the rubber parts, doors, the dash board quality etc etc make big difference in the drive quality.
So, a big difference in both these vehicles.