Nice Pen Paul,
Good Fit, and Finish.
Sorry to hear of your Woes.
I only have those sort of days, on the ones that finish with a "Y".
Regarding the Blank that set up before you could get it all in.
You may look at the possibility of cutting the portion of the Tube not entered, and fitting that piece to the other end of your Blank.
You might have to clean up any glue that has set either on the Tube or in the Blank, before fitting the piece.
Take care to ensure you maintain the correct total "Squared Off" length of the Blank.
It can save you a lot of Heart Ache.
Good luck.
Brian.