Stock update - drum and VCO

Just 1 VCO mod left, and also down to last 2 drum decay mods, neither will be available any more once these few have gone.

The drum decay mod will be replaced later in the year with a different version which will be a little more expensive (£55), the VCO mod will most likely not be returning due to parts, there may in the future be a similar mod, but it will definitely not be the same.

A new mod which takes the place of the VCO mod is coming, but it is totally different and will not be limited edition.

Some other mods are in the pipeline too, but not until later in the year.