Air-ride shock rebuild

To cut a long story short, these shocks came with my 13 in a bag of other bits. Always told they could not be repaired, well there comes a challenge.
The seals were leaking and the balance pipe had been cut so nothing to loose as an experiment in taking these apart. According to the style and part number they are fitted to Z750 customs.
First pic shows the damper adjuster removed.
Second, a home made spring compressor to release the top mounting.
Third shows a bit of butchery to get the retaing ring and old seal out.
The seal is std size fork seal 45x57x10.5.
Replace retaining ring with 58mm circlip.
Fourth shows repaired and fitted.

Good for you, taking on a challenge and sorting it out. Be sure to tell us later on how the rebuild worked out , perferably in a post added to this thread.
What was your choice for shock oil and why that grade??

Thank you.
The oil I used was decided upon by virtue of the design of the shock. To me they resembled the modern upside down forks fitted nowadays, with this in mind the oil I use in modern forks is fully synthetic 5wt. The amount to refill was a puzzle as no data available so working out the approximate volume left when the unit was compressed, 250cc was filled. It will be some time before the 1000 is on the road and may test on the 1300 to see how it works.

Greetings from Silverstone.

A decade ago, there was a California company, Progressive Suspension, that made THE solution for Honda Gold Wing front fork issues, progressive rate springs, and, a complete kit to redo the rear shocks, so less air would be used.

The rear kit consisted of shocks that would accept the air canisters over them, with better plating on their sides so the air seals wouldn't eat it away, and both rear shocks became just that, sealed real shocks with springs on them, NOT just air chambers with oil in them. The air chambers were reinstalled.

When properly done, both ends were golden, fixed the problems, and with seriously less air in both ends, down to under 5 lbs. .

Air in front forks and rear shocks weren't the solution for suspension they were touted to be. The air only caused dead rear suspension and blown front fork seals. The air in both ends was simply to compensate between a 110 lb Japanese rider, and a 300 pound American rider, so 200 different spring sets for each end didn't have to be offered, and it did not work.

I don't think they ever made a kit for Kawasaki 1300. I have Koni shocks on my 13, laid down at a 36 degree angle, works well.