Hi, I am not a pen expert myself, but I would definitely suggest to stay away from using acetone to remove the nib housing from the pen section, as acetone may ruin the acrylic of the pen.
What I would suggest is to try immersing the pen section ONLY alternatively, for a few minutes each time, in very hot and ice cold water, for 5-6 consecutive times. This sudden temperature change should be more than enough to soften the glue between the plastic nib unit and the metal pen section. Very hot water is good, but boiling water may damage the gold plating of the metal ring of the pen section, so kindly be aware. Once you do this, you may use a narrow hollow instrument inside the pen section in order to push the nib unit out towards the tip of the pen (or in other words push in the direction opposite to the barrel). I used the hollow plastic cover of a hypodermic needle that could fit inside the pen section for that purpose, but you can use whatever other instrument you may choose.
If you are willing to try a Bock unit, first I would make sure you have one available and also a corresponding converter alongside, as the kaigelu converter will not fit the Bock unit. I ordered both my components from BeaufortInk in the UK, not affiliated, but depending on where you live, you may choose someone closer to you.
Believe me, you cannot even imagine what a great new fountain pen you will have after you do this modification. The new pen will be totally reliable, it will be ready to write even if the pen has not been used for months, and you will be able to choose/change between different nib sizes, finishes and alloys (Bock EF, F, M, B, XB, calligraphy italics 1.1, 1.5, 1.9 mm, stubs, steel nibs, gold nibs, palladium nibs, semi-flexible titanium nibs - which are my favorites-, the possibilities are almost endless and fascinating. To me, the new pen is equivalent to pens worth hundreds of dollars more...
Hope this helps, let me know if I can be of any more assistance.
Edited by Frank66, 03 March 2018 - 19:59.