Thanks for all your kind feedback!
Today, I managed to mount everything on the new front panel. The total station weight is now 329 g including the MTR-3B, TinySWR indicator, 2S 1000 mAh Lipo battery, DC-DC- boost converter for 9 and 12 V, Palm Pico Single, retractable earphones, volume control, and balanced charger that can be powered by a simple MicroUSB port; all in a watertight and extremely robust enclosure.
Attached, please find a few snapshots of the final result.
73 de Martin, DK3IT
PS: The red and green LED are misplaced; will fix that asap.