AWithZ UF20B spotwelder stand with WP 240 holder

First of all: thanks to Rolfvanr for his great design!

Found some tiny problems:

1. The stand itself is a bit too short, so my UF20B has to be forced in;
2. The holder for the pens are not big enough to store the active pen of the UF20B;
3. Also got a WP 240 that needs to be stored;
4. Since there will be loose plugs I also made them attachable for both of the available pen-types;
5. Made some additional compartments for stuff like nickle strips, files, flush-cutters and tweezers;