I looked up the part numbers and they don't look like what I've seen on here and else where..

looking for 2 new or excellent shape caps and the holding springs.

Nothing special about the caps. Drill the hole yourself. The spring shouldnt be that tough to find..........maybe like a lawn mower/small engine shop would have a few spring options to choose from.

The problem is the oil caps I have leak quite a bit, and they are mismatched. I don't care what it cost, I'm trying to find the correct parts for the finned aluminum covers

Most likely the gasket rather than the cap.

BAM has several springs and one cap in stock.
Genuine Mercury & Mercruiser parts. Cylinder Head And Rocker Cover

To see if in stock, once on that page, click on the part number and it will show you how many in stock.

Edit in: Also hover your curser over the notes magnifying glass icon and it will tell you special info depending on part, like serial # range or something else important

Also, you could call them, they are super knowledgeable. Marc has been around Merc engines for a very long time.

Seriously $25. You can buy a chrome one for like $6. I hope you don't think that it is made by Mercury and it is something special. They are buying it bulk, unpainted from some aftermarket company just like Chevrolet, Moroso, etc. Then it's painted, zinc plated, chromed, or whatever finish.