Two bad clones have been found, they have failed to understand the role of bridge and shielding, and made some bad modifications to facilitate manufacturing.
My unshielded black clone just arrived, 16 days after ordering.
White text is less bold than on shielded black units,
and front bezel is held by 4 black screws,
while others appear bright riveted(?)
eBay seller onemoredeal (Jonna) had explained that delivery was
delayed from eBay estimate (based on speedpak shipping service)
by using alternate (Chinese post) that allows battery,
which was indeed included and charged.
Adding an SMA "protector" to TX did not appreciably impact calibration;
even a BNC adapter does not much affect readings below 100 MHz
Not sure whether description as "bad clone" is entirely accurate;
2017 nanoVNA by edy255 also lacked shielding...
FWIW, shippers crushed outer corrugated box by about 1/3,
but inner nanoVNA box wrapped in foam was intact.
Oristo