Keystone 3003/2990 battery holders

I am working on a project that requires both of these parts, but was suprised to see that the only one stocked by almost everywhere I looked was the 3003. The 3003 is the part that actually holds the battery, and gets the positive charge from it. The 2990 is a small piece that gets the negative charge. As I said, I figured if they would have one, they would have both...but that is not the case. Is their some other part tht is used, or do they make the 2990 out of just a piece of scrap wire?

Thanks

https://www.electro-tech-online.com/custompdfs/2005/06/p09.pdf

(2990 sheet)

Rather interesting to say the least.
I was doing a project that required a low profile coin cell holder for the CR2032 battery. I found this part number at Mouser Electronics.
614-HU20321 Mouser website is www.mouser.com
I have used three of the holders and they work nice.
As a sidenote I have a Keystone electronics catalog and the 2990 part is not listed in my catalog, but the 3003 part is.

I wonder if the part number changed?