Spool adapter for V3 model

Made an adapter to use the uprights from the V3 spool holder to use the Spool Support Arm - Mod RL 2x 608. To use this, you need to glue the part of the Spool Support Arm to it, and then assemble as listed in Rostock MAX v2 - Spool Support Arm - Mod RL 2x 608