I believe for the J-FET, the GM328 pattern testers are only going to show you the minimum turn on gate current and flow. Those look OK in that regard.
I picked up an MTester (LCR4-T4 rev) up just last year.
I just checked an SK68A with it and it matches the datasheet minimums to switch on @.5mA gate, and forward voltage @350mV nominally (avg both ways)
Make sure you test each SGD and DGS (both ways) and they are similar. I believe the tester can't really tell which is source and which is drain when the gate is the center pin.
Again that should mean it's not open or shorted... but not much more than that.
I wish I had gotten this before I tossed my small bin of scrap parts. It would have been fun to check a few things out. :-(
I stuck two known bad transistors I had sitting here reminding me to order parts. One shows ars two resistors (dead short), the other as a diode (one leg open)
FYI, anyone that's wondering what tester was used, check out this monster thread and this review.
http://www.eevblog.com/forum/testge...0/?PHPSESSID=7b40e4d14581c39b9ddd7f63f97d02c0
http://hackaday.com/2015/04/24/review-transistor-tester/
They're modding these kits to do all sorts of stuff.
Best $20 I ever spent. Too bad I haven't found the time to finish up some of my own projects: dead MX-2000 and noisy C-4 (after recap) among them.