That's the boy!
I'm fairly sure that my dad's old one had a red Fiat badge inside the steering wheel, rather than black.. but the seats were identical. They were so wide that for a long time I couldn't remember whether his car had a bench seat ... but then I recall that it had seat adjusters for rake etc. so it must have had separate seats. It's good to see (again) what they actually looked like.
Your "milleciquecento" script needs to be chrome though.. so get it re-plated. That was the high-spot of sitting up front, so it's iconic.
I can't recall if my dad's 1500 had rubber mats over the transmission tunnel... or carpets. He could well have put over-mats in there that covered the hump and both footwells. I remember the ribbed "Fiat" ones.. but I may be thinking of my uncles old 500.
That old instrument console with the "strip"-alike speedo is genius and just as I remember it. The blue high beam light was always the special one.. we hardly ever saw it. The red "MAR" (?) and oil light were on every time he started it..
But... yours looks manual gearbox with the lever on the floor. I could swear blind my dad's old 1500 has a chrome stick shifter on the column but it was a (4 speed?) manual, with a mini H-gate on there. He never had an auto', for sure... so I'm either confused about the shifter.. or he had some random gearlever that wasn't made or didn't exist for very long. I dunno if you know any more about it.
His handbrake may have been in the centre of the tunnel... but now I see where yours is, it vaguely rings a bell (and would be more likely). I remember that between the "bench" seats and the dashboard it was pretty much uncluttered...we could easily clamber from one side of the car to the other (usually when my dad had the car on a jack and was working underneath it.... 1970's!

)
Ralf S.