Hey Joe,
I couldn't find a NEW one.....I did try Part#91262-KA3-712 (SUPERSCEDES 91262-KA3-711) it's designed for a 19mm bushing.....ours is 18mm. So if you can use a larger bushing this may be the way to go.....
Then I was looking in my spare parts bins ....the one buried in the far back of the garage and low and behold!!!!!
Another '86 TRX250R rear shock......with 1 dust cap!!!
I should have gone out and bought a lottery ticket!!!!
John