The Washington DC 48 sedan looks to be an Eight (not Deluxe) based on no upper window stainless and no inserts in garnish moldings

I think Max Merritt carries them

Pour quelle annee/For what year?

Available widths look way too big

I must admit I had not heard of these wheels before. I was prepared to be appalled but they look better than expected. They might work. I would ask questions around the wheel offset. They will result in a harder ride because the sidewall of the tire will be stiffer.

The difference between 3/4 and 5 is not way of manufacture. Dot 5 is silicon, Dot 3/4 glycol. So they are very different chemistries. Lots of debate on this, I have not the experience to share, but there are threads on this. Brake light switch was an issue for some

"I took my awesome Packard to a Packard meet and got judged at 12 points - how can that be?"

Quote:

definitely 23rd series - there are other indications too.

If you like the engine/trans colors fine, but you do realize they are not stock, yes?

Try Hirsch. While I've heard the selection has decreased, he had some good matches.
There were at least three different upholstery styles offered. The standard one was a striped wool broadcloth. There were options for a fine ribbed Bedford cord and for a color-tone which used two colors of plain broadcloth and color-coordinated plastic and reveals.

this may be too crazy, but here goes:
Some engineering students receive a emblem called a "bent" that is meant to resemble a bridge truss. I remember it being sand cast in bronze, and you had to polish it. If you contact a university's Engineering College you could ask where they source them. Or you could contact Tau Beta Pi, the engineering society.

Not sure why you want sand cast - the finish is usually a bit coarse compared to lost wax. Some jewelers use lost wax.

Additive manufacturing ("3D printing") is another possibility using the sintered metal process. Others here have much more experience with it than I.