Here are the files of the latest OpenBSD SGI release. It was 6.7. After that support was canceled.

base67.tgz
boot32
boot64
bootecoff
bsd.IP22
bsd.IP26
bsd.IP27
bsd.IP28
bsd.IP30
bsd.IP32
bsd.mp.IP27
bsd.mp.IP30
bsd.rd.IP22
bsd.rd.IP26
bsd.rd.IP27
bsd.rd.IP28
bsd.rd.IP30
bsd.rd.IP32
BUILDINFO
cd67.iso
comp67.tgz
game67.tgz
index.txt
install67.iso
INSTALL.sgi
man67.tgz
SHA256
SHA256.sig
src-ports-xenocara_31May2020.tar.gz
xbase67.tgz
xfont67.tgz
xserv67.tgz
xshare67.tgz