I remember in the days of craft supplies when they were in millers dale they sold there slimline pens in packs of 5 and they were in two grades one cheaper that the other and the cheep one the nib retracted as you were writing the more expensive one didn't and they gave you this information in there listing perhaps if we all start sending kits back to suppliers and complain to be honest I always do and get replacements at one time by the time I got to a kit I would have forgoten were I got it but now I dont hold such a big stock of kits and mark were they come from so if a kit is dodgy I know who to contact.
One of the run of the mill kit I do like is the Lucida pen I have mentioned this before same design as the sierra but slimmer and shorter Pen Making :: Ball Point Pens :: Lucida Pen Kits - Pen Kits, Pen blanks, Clock Kits and wood turning accessories. the cap end fits positively the mechanism is a good fit and very positive but there is a slight raised bit were the band meets the nib that could be a bit better
So thats me done good night