Sometime around 5+ years ago I recall contacting them about some replacements and was told that no more were available...
(I have a couple of new-old-stock spares reserved for the day when we spruce up our boat to sell it. )
Seriously, after our re-rig a few years ago we never again put anything on those tips. Our rigger believes that most enclosed spreader tips invite moisture and corrosion, and that we are better served by keeping an eye on the genny aloft when cranking it in that last bit.
So far so good, and I have not yet had to patch that genny!
The other vital Kenyon vinyl bit that seems to be permanently MIA is that nice molded mast collar boot. I am keeping ours patched with sealant... but it is just barely functional...
Good luck on your search, and I hope that one of the site members has found a new source for this stuff.
A lot of other owners of 80's Ericsons could use these parts, as well.
Best,
Loren
ps: link to prior thread with similar concern:
http://www.ericsonyachts.org/infoexchange/showthread.php?t=3016