No doubt
it was reassembled into its present position, despite the in situ appearance.

Figure 1. There is just no way to avoid reflections on this stairwell specimen of Pteranodon, if you want to capture the whole specimen in one shot from a distance.
Mizzou has very few other vertebrate fossils.
The University of Missouri (Mizzou) Geology Department has a wonderful and complete small ichthyosaur from the Holzmaden and they have a partial parasuchian skull from the Petrified Forest. I don’t think the Mizzou Pteranodon wing has a number. Small portions, like the wrist and free fingers are restored.

Figure 2. The Mizzou Pteranodon wing is average in size and not very robust or gracile compared to others shown here. Click to enlarge.
If we take the wing at face value
and place it in context with other Pteranodon wings (Fig. 2), we find that it is not the largest, nor the smallest, not the most robust, nor the most gracile. The scapulocoracoid is relatively small. This could be a chimaera.
And while we’re on the subject of variation,
it is worthwhile to consider the post-cranial variation in Pteranodon, a subject we touched on earlier here and in figure 2, but has not been adequately addressed elsewhere. The lack of more than a few skulls matched to post-crania (Fig. 2) has hampered efforts, but a decent cladogram of Pteranodon interrelationships can still be managed.
…at least if we assume no ontogenetic changes at all.
No assumption necessary. You’re referring to an old paradigm that has gone the way of dragging tails in dinos, but still resurfaces every so often. Pterosaur specimens and phylogenetic analysis demonstrates that they and their relatives develop pretty much isometrically. Of course, we don’t expect long and tall crests to fit inside of an egg shell.