I saw a back seat and centerconsul for a 2000 spider on E-Bay and wondered if it would fit my 1973 124?

yes they will

when wanting parts and needing to know if there the same
go to a supplyer and look for the parts to see if years differ
if they dont there will be more than one part with dates



good luck

I tried your idea with the center consul and found it will interchange but no-one lists the back seat. Even if they did list it, a change in the fabric or patern would cause a different number to appear. This is why I'm having problems with the interior parts.

The center consoles are the same for all years.

The back seat will fit as it has the same overall dimensions, however your 73 came with 2 point seat belts (lap belt)where the retractor is mounted on the floor behind the drivers and passengers seats. In 1977 Fiat introduced 3 point seat belts (lap and shoulder belt) there is a retractor mounted in the seat back portion of the rear seat on each side.

So if you order a later rear seat back and install it in your 73 you will have two holes on each side of the rear seat back piece. The rear seat bottoms are pretty much all the same.

From 68-78 all the seats, front and back had narrow stitching while the 79 and later seats had a wider stitching.

Thanks for the advice, it was a big help as mine did not have either.