battery tray, new modification I made this modification because someone offered good $$ for the yellow tray and I could not resist the $$$
The second photo showed cut short 3mm screw. The battery tray is mounted on 5mm thick M3 nuts, so I cut 8 pieces of 3mm screws down to 2.5mm thread height, then screws 'bite' into the 5mm think M3 nut from top and bottom engages 2.5mm each. Rock solid!
the tray mounted on 5mm height M3 nut, the M3 screws are cut short so that only 2.5mm thread engages ...