OS "GF piston filler" in classy black celluloid

[Fountainbel]

Hi all !
I was lucky to get a short rod of black celluloid, being actually the most difficult to find celluloid.
After some considerations I decided to use it for a MB139 inspired GF piston filler
The rod was just long enough to make one two different barrels.
A “long ink window “ version which is shown on the picture below, an a "standard length" ink window version, which I will probably also make.
Surely would appreciate your opinion on this pen, do you think a normal length ink window would look nicer on this pen?
On the pictures below you can see the pen featuring the long ink window.
Thanks in advance for your valued input !
Francis
PS :Note that on the un-capped pen one can see the piston screwed fully out, ready for filling..