Look on Rig-rite site for NB-32 boom and then pin you refer is I believe:
NB2 Horizontal Gooseneck Pin: NB2-3:
Buy
Clevis Pin is 10mm (3/8") dia. x 49mm (2") long. Used to attach the NB32-1 Gooseneck to Isomat Vertical Gooseneck Toggle Pin, NB2-1.
Hayden has nice story on his blog is reefing improvements with pictures:
IP35-boom refit
svislandspirit.com/ip35-boom-refit-to-single-line-reefing/