1961? Olds super 88

[rattle can man]

As someone not up on GM products, what other cars shared the platform? it's possible someone did repairs using quarters an rear panels form something else to save the car since replacement panels are rare. Just my 2 cents.

[Brian Austin]

The basic body shells were B-Body for the 88's while the larger 98's were C, IIRC.  They didn't share chassis with other divisions.

[rattle can man]

According to Wikipedia, the B-body was shared with Pontiac, Buick, and Chevy. From what I can see, only the Oldsmobiles had the skegs. General Motors B platform - Wikipedia. If that is the case, I'd venture parts from one of the other models were used to repair rust or accident damage because of the parts being scarce. Or someone put an Olds front clip and badges on one of the other B-bodies.

[Falcon Ranchero]

The closest looking lower rear quarter on any other 1961 GM would be from the full size Buicks; based on looking at the Olds in question and a same year Buick

[rattle can man]

I would guess a LeSabre donated lower quarter panels and bumper, but we really need a better picture. An Invicta would be another option. It looks like all b-body olds had the skegs. Chevy and Pontiac look to have different wheel openings.

[Can-Con]

Personally, I wouldn't even hazard a guess until I see a pic of the back of the car. 

It's "Schrodinger's car". 😉 

[DJMar]

Since we've only got the one pic to go on, I'd say this one is going to remain a mystery until someone runs into the owner of the Olds and gets a definitive answer.

Just because cars are built on the same platform doesn't mean all body panels interchange. It's possible that the owner of the Olds used '61 Buick or Pontiac parts - it's not any easier to find them, btw - but there are huge differences in the rear quarters, rear bumper, tail light panels and trunk lid between these cars. Making everything work together would be an intensive, and undoubtedly expensive, undertaking by a skilled autobody shop.

I'm not saying it couldn't be done. As a custom job, it certainly is cool. But until we get more info, we're all just spitballin'.

[Falcon Ranchero]

I absolutley agree; I'm honestly extremely surprised that a single lower quarterpanel abnormallity on an otherwise stock Olds has generated this much attention and possible answers as to why the car is like this. And I mean rightfully so because we are all aware of the "skegs" which were pretty prominent features on the car, so the very clean, stock appearing absence  of such is generally puzzling.