Hi Kath and welcome to the forum.
A few things that will help you.
The kits will have tubes in the bags, if they have two tubes then they will usually need three bushes, one tube they will need two bushes. That's the easy bit..
I would mark up the plain bags with numbers for the different kits.
What you will then need to do it get your bushes to fit the tube ends, that is simple and would mean trying the bushes in the end of the tubes. Once you have the bushes that fit the tubes you can put them in a pot with the number of the kit that they fit.
Then the next step, which would be easier with a set of digital calipers..
Take each kit and measure the widest part of the nib, centre band and top, you can then get each bush and measure them and match them up.
Not the easiest way to describe but sure you will get the gist..
If you need anyone to talk too then pm me and I will give you my telephone number to talk it through with you.
Hope this helps..