Hello all, I won this pen off an ebay auction for $42 a few days ago. It was listed as a Parker 51 vacumatic. After receiving the pen it says Parker Duofold 1 on it. I tried cross referencing it on sites like Richardspens to try to find out aproximate year that mine was made, but I'm having a hard time finding one just like this. I've found ones similar but they usually have a solid gold band on the cap not the two gold lines, or some minor difference. As far as I can tell it doesn't fill with ink, guessing bladder needs to be replaced. It was described in the auction as not tested with ink so I wasn't surprised. Can't for the life of me get the nib housing to unscrew from the body of the pen, actually twisted the nib around a bit but it went right back into place, no damage. Only other thing is it's missing it's clip but I found some on ebay for around $25 so I'll pick one up. Not sure how to attach it tho since the end of the cap has a small plastic threat like something should screw in and all the replacement ones I see look like just a round circle, so I guess I'd have to glue it on or find that cap that screws on. Anyhow any advice or help would be greatly appreciated, thanks.