OK I know not if XL450's and 450A's are the same but my forks are polished alloy, bolted together with a canti hanger built into the fork bridge.
Removal of dust caps shows an adjuster that you rotate left or right to adjust rebound via a hex key. Unscrew this hex key adjuster and the elastomer is beneath, long transparent blue elastomer with two white plastic holders at either end. Beneath elastomer is the hex screw that stops sliders coming out of the legs, you'll need a long hex key possibly on a socket set extension to reach it. No springs exist as far as I'm aware, I've never stripped them completely.Grease all the sliding bits and reassemble.
I also have a sprung Ballistic fork, broadly the same as the 450's but the spring lives at the top of the sliders held in with a spring clip.
Personally I think Ballistic forks are rather good as basic Taiwanese forks go, but have never been popular or common in the UK market. They were more common in the USA, we're more familiar with RST's for example.
Hope this helps, post a pic if you can, I'm just interested to see them.
Cheers Velo