Does anyone have a good source for Attwood Springlift gas springs? I need an SL2-20-1 for the ice box lid on our H336. I found one a couple of years ago, but it has already worn out and I cannot find a similar replacement. I've scoured the internet, and this particular model doesn't show up anywhere. It has blade ends, is 15" extended and 9.5" compressed, 20 lb force.