The Freestyle was sold as a kit conversion and not a kit car so the chances of ever finding any spares is very unlikely.
You don't need to wait until winter, my front cycle wings are solid I can sit on them, if yours are likely to fail best to get to it now. It is not much fun when they do!
The welds just need grinding/cleaning up and then get as many beads of weld on as possible on the flat plate. As said before they have a really hard life, every post hole or bump they get a bash and they are on the unsprung side.
See pics, this is what I have done for the rears. Found some scrap aluminium plate 1.5mm and cut a T shape for the hanger and then cut a square for the attachment to the the box frame. Works well and is super simple, you could get this added in a morning and won't cost anything if you have some scrap ally, a hacksaw and a drill etc.
The edge trim is only on there for IVA purposes, haven't got round to binning it yet.
Hope this helps...
Good to hear you have done over 500 miles since you bought yours