The newer 451 alloys suit the older car quite nicely. The updated designs make the car look more up to date.
Yes at the front and no at the back.
Here are some "Design 3" alloys originally fitted to the front of a 451. They fit the front of the 450 perfectly.
The slightly larger offset makes them sit in the arches far nicer than the originals.
Same with the "Design 8" alloys from the 451. They fit nicely...
...and sit closer to the edge of the arch lip.
If you try to bolt some standard 451 rear alloys onto the rear of your 450, you are in for trouble.
The 450 expects a rear offset -1mm, so putting on an alloy with an offset of 34mm will cause the alloy
to sit so far into the arch that the tyre will touch the shock absorber. It won't even properly bolt to the hub.
The answer is to fit a spacer to bring the alloy away from the suspension.
The difference between 34mm (the 451 alloy) and -1mm (the expected offset) is 35mm.
So I contacted Superforma and bought a pair of 35mm spacers.
These were securely bolted to the hub using the bolts provided with the spacers.
The 451 rear alloy is then bolted securely to the new spacer.
A 35mm spacer in this instance was perfect and made the wheel sit perfectly in the arch.
Most 451 alloys will fit exactly this way.
If you have the black arch extensions over each rear arch on your 450, you might want to consider 45mm spacers
instead of the 35mm spacers shown above. This is because the arch protectors are 10mm wide so to line the rear
alloys up with the edge of the arch with the protectors on, you'll need a little bit more width.