Hi Guy,
Reviving this post after an unplanned Christmas hiatus!
There are a number of differences between this saloon and mine.
Mine is a 1300 and from the very late Series II model run which I have worked out to have only run from January to September 1979 before the Series III was launched. This looks to be an early 2nd series 2000.
The very late 1979 model run cars are easily indentified by the longer gutters as oyu correctly mentioned, but other diffences from the other two Series II model runs are as follows:
1) On very late cars, all interiors have the soft woolcloth seats and trimmed door panels, headlining, pillars, parcel shelf regardless of engine size (first revision of series II production had this, but only on the 1600 and 2000) The earlier Series II cars have much harder cloth trim (1600, 2000) and 1300's nylon trim with flat vinyl door panels (1300 and very similar to Series I) All earlier 2nd series have a perforated white vinyl headlining. Very late Italian only market series II cars could be specced as "Executive" and they had the "L" Cloth more commonly seen in the Gamma.
2) Late Coupe / HPE style "Ferrari" stalks for 3 spd wipers on 1600 and 2000 only
3) Fully carpeted boot (instead of a rubber floor)
4) Black sill rubbing strip as opposed to chrome
5) Electronic Ignition (usually marelli)
6) Air intake scoop and valve style airbox rather than the pre-heater hose running over the top of the engine.
7) Later clear type of fuse box cover

Bottle instead of bag for screenwash
9) All cars now have the glossy badge wheel centres whereas with earlier series II car the 1300 had plain pressed stainless steel centres.
Differences from very late 1300 to 1600 and 2000
1) Lower geared diff for improved acceleration - (don't ask me the ratios!)
2) 4 Round Cibie headlamps, black headlamp surrounds (different from series I cars!) and a matt black plastic grille. (the only reason mine "had" to be a 1300!)
3) Earlier Berlina / Coupe / HPE style stalks for 2 speed wipers (no intemittent on the 1300)
4) Narrower 155 / 80 wheels - (now trickier to get tyres for!)
5) Two rather than 3 accessory switches
6) Cheaper plastic badging - rather than the nice metal badges!
Hope this helps - I can't think of any more differences off the top of my head!