George, I did not turn this cap but I have made several just like this one for the replica Parker Centennials that I turn. Most of the pens I turn now, I make the cap bands. I do not shrink bands on to caps. I use two methods. The one most offen used is to cut a groove on the cap where the band is going to go, approximately 0.0070 deep. I use 14kt.gold banding material purchased in band form from
www.riogrande.com. That material is approximately 0.0120 thick. After cutting the band groove, I use my caliper to measure the bottom of the groove, that measurement X 3.145 ='s the diameter of the cap at the bottom of the groove. Once I have that length, I cut a piece of banding gold, solder it together, clean it up and lay it aside. I then turn a radius from the side of the cap closest to the end of the cap (normally the length of that radius is approximately 1/8 inch). I then reduce the side of the groove closest to the cap end by approximately 0.0020. That makes the sides of the groove uneven but not enought to be detected by the human eye, but it reduces that side enough to let the band be swedged onto the cap without cracking the cap. Once the cap is in place in the groove, it is glued in place with a small amount of CA glue. Then I chuck the cap up in my lathe and turn the band down to approximately 0.0050 above the surface of the cap. I sand it then with 600 grit wet sandpaper, then again with 1500 grit wet paper. The I move to the buffer and polish with to or three grits of polishing compound. Be careful not to get it too hot with sanding or polishing.
It takes practise, but once you experiment for a few pens it becomes very easy to do. The second way is about as easy but requires a splice of the cap under the band.
I have been very successful using both of these methods. I know there are others who use different methods, but I am happy with the results I have been able to obtain.
I hope this helps
Chris Thompson