It looks to be an Artisan Executive Rollerball from CSUSA. I think you have all of the parts except for the spring at the end of the refill which is not in the picture, nor is the refill. Don't think it is a closed end pen.
Traditional style and moderate heft of the Artisan® Executive Rollerball Pen Kit make this pen a favorite among executives. 10k gold plating Quality rollerball refill Specifications:Finished size: 1/2" x 5-3/8"Minimum blank size: 3/4" x 3/4" x 5"Includes:Rollerball ink refillPen components...
woodturnerscatalog.com
Do a good turn daily!
Don