Arrived and I've looked at them
I have received these kits and I note the following - the transmissions are indeed partly plastic which, in and of itself, means nothing at all. I've tried about a dozed (20% of those I received) and they all accept a refill and operate smoothly and correctly.
The upper and lower tubes are not interchangeable the lower tube is longer because the transmission is shorter. This version the centerband is definately not in the center - the lower barrel is longer than typical and the upper tube is shorter. The overall length of a completed pen is about typical give or take a tad.
Do something different (for most of us) and read the instructions first especially about pressing in the transmission.
The refills seem typical - neither exceptionally good or exceptionally bad.
The blanks are not marked as to wood species but they appear to be uniform in length and size about 3/4 x3/4 x 6. Mostly they are, as you should expect, plain jane blands without a great deal of grain but will make prefectly good pens.
Finish on the metal parts seems to be about typical and the parts themselves are perhaps a little lighter than you'd get on Fancy Slimlines. The clips are a tad light but seem to be adequate. The centerband is not as wide as typical being maybe 2/3 the width of a Fancy centerband and 1/2 the width of a standard slimline. The pressed in parts seem to be sized about right for smooth easy pressing and for those who like to glue them in to be sure, gluing shouldn't be a problem.
Just as an aside - these are not 'made in China' kit -- they are made in Taiwan.
If you would feel more comfortable with an all metal transmission you must keep in mind that it will need to be pressed farther into the tube than for other slimlines - measure first to get the approximate lenth of the transmission that must remain out of the tube.
I will use these kits as pens for troops, perhaps not all of the blanks will get used, but the metal parts can be made into perfectly good pens.
Just so everyone knows, although I sell 7mm kits I do not sell any slimline kits and have no axe to grind here one way or the other.