Mellif Stick Transfer Pump Black&Decker 18V battery holder upgrade

Chinese manufacturer Mellif makes great budget cordless tools, and a stick pump is among of them. They offer options for DeWalt, Makita and Milwaukee batteries, but I'm at the Black&Decker camp. So I removed makita-compatible stuff and replaced with Black&Decker adapter, made of two halves and an insert.

Compatible with 5 and 10-cell Black&Decker batteries, e.g. 1.5, 2.0, 4.0 A*h

Original Makita-compatible removed parts on the last photo.

Additional materials needed:
Inox/nickel sheet/stripe 0.8-1.0 mm thick and 6mm wide for terminal insert, 2 pieces of 30mm long.
Soldering iron and corresponding flux to solder 2 wires. Temperature terminal is not used in that tool.
Printed with PETG on Anycubic Kobra Max.