Pilot Emperor Urushi Black

This Pilot Emperor Urushi Black has no cap ring.
the golden clip only has "PILOT" engraved, no "JAPAN", nor serial number.
The #50 14k nib has no size stamped,

14 KARAT GOLD

"PILOT"

REGISTERED

PATENT OFFICE

-< 50 >-

最近收到一支較早版本黑色的:
- 筆帽無金環;
- 筆夾上僅刻有PILOT, 沒有"JAPAN", 也沒有號碼;
- 50號 14K PILOT 筆尖 ，沒有刻上筆尖的大小。

Other information:
Namiki Emperor Urushi