A quick search turned up this Ebay listing:
Honda Odyssey RA1 RA5 Rear Firestone Coil Rite Air Suspension Assist Bags | eBay
It looks like ARCHM Suspension out of Australia is behind the site in the sopallachan's link, and the Ebay listing. The Ebay listing says that the Seller may not ship to the US, and the Seller has closed up shop and may not respond to e-mail until January 18th.
The Firestone Coil Rite catalog does not show a product for the 95-98 van, but does show one for 99 and up. Honda could have produced different vans for the Aussie and US market. So the ARCHM listing of 95-00 could make sense, for that market.
eTrailer lists replacement springs for the 4133 kit:
https://www.etrailer.com/Accessories-and-Parts/Firestone/F6018.html The replacement spring is a 6018. The Coil-Rite air line kit is part number 2131.
A complete 4118 kit, with two 6018 air bags, fittings and air line can be had for $105 with free shipping:
4118 Firestone Coil-Rite Rear Air Spring Kit for Coil Spring Suspensions - TruckSpring.com
The air lines would exit the bottom of the spring. On the RA1, the bottom of the spring is open. If air pressure was lost in the bag, the bag may fall out of the spring, depending on how well the bag fits in the spring with 0 PSI. Comparing pics of a 1998 model year rear spring and 2000 model year coil spring, there does not appear to be much difference besides the size of the springs. Both are open at the bottom.
The piece that is missing from the 4118 kit (not specifically recommended for RA1) that was pictured with the 4133 kit (which did list RA1 as an application) is a retainer plate, which was a round disc that fit in the bottom of the spring and hooked over the coils. Looking at the thickness of the retainer plate, it seems unlikely that the retainer was made to withstand pressure from the air bag. It seems more likely that the air bag, when inflated. stiffens the spring and increases the spring rate. The purpose of the retainer may have been to keep the air bag in place during installation (when the air bag is deflated so it will fit inside of the spring). If air pressure is lost, the air bag may slip out of the spring unless some other measure is taken to retain it.
The Air Lift 60815 kit (4DCurvs link above) has a flat plate that Air Lift refers to as a heat shield. It is used to shield the bag from hot exhaust components.
I don't know why Firestone and Air Lift have no listings for the 95-98 vans. There could be too few vans on the road to justify testing and supporting the product. I am leaning towards trying the Coil-Rite 4118, as it appears to have a nice air line fitting on the bag.
