Deal AJ.
 I’ll scrounge up some hand tools, drills, teenie bits, even teenier bolts, glues, etc and we can have a bang up fixit visit session. 

Today we took a roadtrip to Ohio’s Amish Country where I sorted through thousands of buttons a huge fabric store has in a huge bin.  I loaded a ziplock bag nearly full of buttons I hope some of which can be used to fashion buttons for lost-button chromatic slides.  We can experiment at Danny’s so please someone, bring your broken slides and a lot of ingenuity.

Doug, I searched my supplies and didn’t find my collection of assorted pins.  A few hours later my seamstress wifey brought a zip lock bag full of smaller bags with different pins including MY collection and a few “ older” pins she has had for several years.  Hopefully one will be perfect for your needs. I’ll take them and a few tools to Danny’s party.

I remembered a few years ago I  had tried heating a pin to weaken it but, alas, it turned too soft and I couldn’t get it tempered back to its original springy.
 
Also I will take some BB/pellet shooters, just in case we decide to mutilated tin cans. 

When I didn't have a good #2 safety pin, (at least I think it's sposta be a #2) I've had decent luck by bending the heel (the short end) of the spring using two pars of needle-nozers.

You can try weakening the spare spring by heating it to red then quenching, but that’s not scientific.  It takes skill to temper “ just right”.
I’ll dig up some various pins and some hand tools to experiment with at Danny’s.  That should be enlightening.