@Jans husband @Curly
Hi Mike ... me again !!
Firstly ... with regard to different manufacturers ... most that I have used stick to very closely the same brass tube lengths ... 2.21 for the twist and 2.42 for the click. . Kit names differ with manufacturer, but the name "Sierra" (which is the Berea product name) sometimes gets applied to all.
Next ... disassembly is not easy.
You say that your pen is too long for the refill ? . So let's clarify which kit did you actually use .... is it a Berea kit ? . What Berea part number ?
The thing is ... even within the Berea "family" the kits have changed over the years and the Berea documentation itself has not adequately kept track of the changes. . Also, the documentation for some of the older kits is no longer available on the Berea website.
If you have an original Berea Sierra Click, ( if memory serves the part number begins with 7502 but I could be wrong ) you need the supplied refill extender in order to use a standard Parker refill. . However, the Uniball 207 refill will fit without the extender.
The extender is not hard to make from a brass or aluminum rod or even from a scrap piece of acrylic blank material.
It is just a cylinder of length 0.50" and diameter 0.23". . The cylinder can be solid.
One end of the cylinder has a protruding "nipple" which is 0.18" long and 0.075" diameter, but these dimensions are not critical.
The purpose of the nipple is to fit into the hole at the top end of the Parker refill ... a snug fit is better than a loose fit but doesn't matter from a purely functional perspective. . A loose fit will allow the extender to fall out and get lost at the time of the refill replacement.
So ... BEFORE you try to disassemble, make sure whether or not you are missing the refill extender. . You can easily make the extender on lathe.
It does not take long. . You cannot buy the extender as a spare part.
And how do you know if you are missing the extender or not ? . You will need to make some measurements on the fully assembled pen.
To make these measurements you will need a vernier caliper. . Do you have ?
Let me know if you need instructions regarding the measurements and I will then try to put some detailed instructions together for you.
To repeat ... DO NOT ATTEMPT DISASSEMBLY YET !
Cheers,
Mal