Didn't Gene Winfield make a bolt-in grille bar that looks just like the one in your convertible? I swear I saw them advertised somewhere a while back, I was assuming that's what it was, although it also looks a lot like a 52 Kaiser hood bar (the piece attached to the end of the hood). That's just a guess though. Yours looks like a 2 piece setup though and I think the Winfield bars are one piece, making me think that yours might have been custom cut down from something else to make that bar. Someone did a really nice job of it, whatever it is.
John M's post #88, in the following thread, looks like it has that grill in it. https://www.jalopyjournal.com/forum/threads/show-me-your-shoebox-grilles.506429/page-3
That definitely could be, too. This is the only picture I could find of the Winfield bar, and it's one made for a Shoebox and not a Merc, not the best pic but all I can find. It's entirely possible the Winfield one is patterned after those old Cal Custom ones, or even that they're made from the same dies. If it's tied to Cal Custom or Gene Winfield, that's a pretty cool piece. If I had one of those bars I'd run it in my Merc, I like the look.
Now after reading Joe Blow's linked article I'd say for sure the one in your Merc is the Cal Custom standard bar, with the center molding strip on it. That article even mentions the Winfield bar as a reproduction of the Cal Custom pieces, although I think all of the Winfield ones were one piece like the "deluxe" Cal Custom ones. Really neat piece being one of the original old ones.
The grill is a Windfield style Cal Custom bar grill avaliable from ad's in 50's car magazines, the diver in the center nails it as an original custom aftermarket piece. Great looking Merc. Here's a pict of the Windfield grill in my old Merc, it's all one piece welded in the center with no devider.
Another Windfield 1 piece grill in my 51 Merc, I really Dig your red merc convertible with the 50's grill in it.
I don’t..I’m sure it’s a custom cap made up of a couple different caps of the time. That’s the great thing about hubcaps and customs..easy to make something cool and easy to change up.
Not sure on the centers but Mimetic made wire wheel covers for Ford and Olds in the fifties. I think early T-Birds had them.
That's a bogus plaque that someone is making and selling on eBay. UT and Bonneville were added. Here is what the original plaque looked like ... If you're looking for a plaque from Ogden or anywhere else in the world, check with O'Brien Truckers.
The T-bird ones are currently reproduced, but they're kinda pricey, about $110 each without the center cap (which you wouldn't use, they're Ford specific centers) and also they mount with special clips instead of built-in teeth like a trim ring and they're a real bear to get them to fit even if you have the right rim, the clips are made for a specific wheel depth and even then they're kind of a bastard to get on there. I worked at a T-bird restoration place for years and I remember them well. Certainly a cool looking cap, the customized ones are pretty and are very unique, but not very user-friendly. I think if I was going to use them on something custom I'd eliminate the clips and attach them to the inner part of a trim ring, like the guys with Cadillac Sombreros do.
Consider changing the exhaust tips, the tips on the car are 60's / 70's slash cut tips, they should be 50's style Pencil Tips like this.
I wonder if these '50 Dodge truck dash speaker covers (or is that a vent?) would be big enough to cover those door panel speakers? They'd be period correct and very un-obtrusive, although they look like they might be a little too small. I'd bet Cal Custom must have offered speaker covers at one time too, although the big musical note ones are kinda flamboyant for a custom like this. I really like what you did with the Bill Smith '34, getting all of the visible details period correct again, and those speakers are the only things that stand out on this Merc convertible, that's why I bring it up. I really do like the car. Pencil tips on the exhaust would look nice, too, and are easy and cheap.
From the 1966 JC Whitney catalog. I guess they wouldn't have to be round, as long as they covered everything.