MrB, I e-mailed Weber and asked them to reconsider an 18.5" model with ash catcher, but just received a "We will bear your suggestion in mind" response - a TVM & PFO e-mail!
Weber wobbly leg syndrome is a known malady, but in my case the socket rusted so badly that the old Weber had to go when I could see daylight through the bottom!
Let's hope the weather-guessers can conjure up some fine Wx again soon - I'm fed up with this wind and rain!