Sounds like you have your personal computer museum. ;-)
I have four laptops in the closet with various flavors of Windows. All are missing the power cables and they aren’t cheap anymore.
Maybe I’ll take them and try to find some cables just to see what I have.
I know the oldest is an HP with maybe 95 or98 on it, one is a Toshiba with XP and no idea about the other two.
They gravitated to me over time. The Toshiba I bought new and used it for many years. The hinge broke and it was cheaper to prop the lid up when I used it. The power cord to that one went into the ether several years ago.
Oh well.
That actually is what I do have... I had a serious case of ETF (Electronic Trinket Fever) and wasted an unreasonable amount of money on this now mostly worthless collection. I have a hangar full of ancient computer equipment. Some of it has become very difficult to find and have some historical significance. One of these days we will move to a smaller place and I will have to dispose of most of it.
You can probably find a power supply that will have enough interchangeable plugs to handle most of those old laptops. Unfortunately, old laptops can be difficult to revive. The CMOS battery will have gone dead years ago, so you will get some error messages at it starts up. If the hard drive has not been run in years there is a very good chance that it will have problems. Old desktop hard drives often have difficulties as well depending on how they were stored.
Here is a universal laptop power supply that I have had good luck with:
https://www.amazon.com/gp/product/B0132ST35Y/
It comes with 16 tips, but you may have to purchase an additional set of tips or a different power supply to get the tip assortment that will work best for your laptops.