We've now have a file structure in Github (see etherpad), according to the official categories of weather and symbol groups. Each file is one SVG symbol. I have 64 more symbols that when we started.
More symbols are being drawn from scratch in New York and are being added to Github repository too.
These repositories need merging.
There are a number of issues identified which cannot be addressed quickly without exepert advice - these are listed on the etherpad too.
Even though symbols look clean and fit for purpose in browsers, the underlying SVG/XML code generated by different editors is often rather messy and unnecessarily complicated.
Still have to add to Wikimedia acommons, so lots left to do in the next few weeks. But GitHub will do meanwhile.