The " Jr. " designation refers to a "family" of pen kits, sort of epitomized by the general architecture of the " Jr. Gentleman " pen kit. . .
See for example :
https://www.woodturnerscatalog.com/p/2/6696/apprentice-Jr.-Gentlemens-II-Pen-Kit?term=jr.+gentleman's+pen&term=jr. gentleman's pen
There is also a " Gentleman " pen kit, or commonly called a Full-Size Gent, which is a little larger.
Notice that the naming often includes a number, such as " Jr. Gentleman 2 ", or " Jr. Gentleman II "
That started about 12 or so years ago when very slight design changes were made to the " Gentleman " kit, yielding the " Gentleman II ".
The " Jr. " or " Junior ", obviously, refers to a reduced size version.
There is quite a large " family " of similarly shaped pen kits including, but not limited to : Jr. Antony ( my preference, a gorgeous kit ), Jr. Aaron, Jr. Statesman, ..... and a raft of Jr. This and Jr. That. . . I think that most of these originate at the Dayacom company. . . The PSI Majestic kits are modelled on these, I believe, and include a " Jr. Majestic ". . . The distinguishing feature of all the " Jr. " kits is the size of brass tubes used, a 12.5mm brass tube for the cap and a 10.5mm brass tube for the barrel ..... the lengths of the tubes are much the same but there are differences.
The " Jr. " family of pen kits are mostly rollerballs and fountain pens, but there are some ballpoints, if I am not mistaken.
Now, on to the " Sierra " pen kits. . These are some of the most well-recognized and well-respected pen kits ever. . . The original Sierra, it would seem, originally comes from the Berea Hardwoods company. . It has been around for a long time .... 20 years, or so ?? . . You will find closely similar pen kits from a number of companies ..... I won't even try to list them all because I would be erroneous about some, there are so many.
These are all ballpoints, operated by a twist action or by a click mechanism. . They are all single-barrel and use a Parker refill.
Watch for the names " Wall Street II " from Woodcraft, " Manhattan " from Rockler, " Gatsby " from Penn State Industries.
There are also versions named " Mesa ", " Zodiac ", etc. , etc. , etc.
If you become overwhelmed or confused by their similarities and differences and names, you are in good company !!! . . Tiny differences in styling attract different names ! . . Don't even try to keep them all sorted out in your mind !!!!
After a while, they all get called " Sierra " !!! . . The common feature is they all use a brass tube with so-called nominal diameter of 27/64", and they all use a Parker-style refill.
Just kidding. A friend gave me resin blanks and it said Jr. on it. So to me it means any pen kit that has 12.5mm and a 10.5 mm tubes would work and the Sierra any kit with a 27/64 tubes if that's correct. Thanks that helped a lot.
