Excellent find!!
I'm keeping this in mind for when I get my cab off and (probably) need to renew the shackles.
[on edit] Just ran across this:
Shackles. Although the shackle links aren't that difficult to fab, if you can find one that matches up, these aren't that expensive.
Unfortunately the longest eye-to-eye distance I see on that page is 3 1/8". The 3100s use a 3 3/4" eye-to-eye distance on a 3/8 thickness steel with 1/2" bolts. I simply used the same thickness steel and made up 4 pieces, 5" long to match the originals. The shoulder bolts arrive today so I should have the shackles back on the truck tonight all being well.
In case anyone else is trying to work out whether it makes sense to make them up the bolts cost @$30 for 4. The steel I had laying around but the link below shows you can get a 3' length from HD for $11.
https://www.homedepot.com/p/Everbil...-Bar-with-3-16-in-Thick-801867/204225719So, @$41 all in with enough steel to almost make two complete sets although this does not include the eyes which would be more difficult to replicate.
They seem to be of a thicker steel (1/4"?) and show zero wear.
