Okay, I've updated by UCM TF count with Article20's new ruling about customs.
So after reading and talking, here's how I've decided to count my customs:

+ Goktimus Primal - doesn't count because:
* use of KO "Dragoonball GT" head and Sculpey neck is in violation of Article01.
* junker Optimus Primal body is in violation of Article19

+ Goktimus Prime - counts.
* While the base body is incomplete, it's not a junker. It still transforms from a robot to a truck. There's no trailer, but a truck is still a truck even without a trailer (otherwise Huffer and MP Magnus would be screwed).

+ Lexicon - counts.
* base toy is a straight repaint of Classic Goldbug.

+ Machine Wars Jetfire - counts.
* base toy is a straight repaint of MW Skyfire with faction sticker replaced.

+ Motordrone - counts
* base toy is a straight repaint of BM Mirage.

+ Sentinel Prime - doesn't count.
* Straight repaint of a bare G1 Rodimus Prime toy, but unlike a bare Ultra Magnus robot, Rodimus Prime is unable to transform into a vehicle without his trailer; he's only half a truck.

+ Vok Hunter Tarantulas - counts.
* Straight repaint of Transmetal Tarantulas. Even still has his pizza-cutter. (:

So out of these 7 customs, 5 of them would count under UCM.

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Regarding Article19
The definition of C6 (or "junker") can be very subjective and we all have our different definitions of what counts and doesn't - that's entirely up to the individual. Article19 works like this - if you think it's a junker, then it doesn't count; likewise if you think a toy isn't a junker, then it counts.

Here are some articles which I used to help decide what I counted as C6/junkers or not.
http://www.he-man.org/primary_sects/...ingterms.shtml
http://stason.org/TULARC/child-paren...cale-mean.html
http://www.antiquetoys.com/adzoid/gradingguide.php3 <--I've used this definition of C6

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[u]Regarding the counting of Goktimus Prime[/ul]
I was intially hesitant to count Goktimus Prime, but then it dawned on me that I already have two Ultra Magni in my collection, a reissue w/ trailer and a G1 non-reissue that is only the cab robot (I've replaced the fists with reissue fists and the gun is from the original toy). I count both of them because I don't consider the cab-robot to be a junker. I have G2 Prime that is only the bare cab robot, but I count it. My G2 Prime uses Pepsi Convoy's fists (because I display my Pepsi Convoy in truck mode).

I know that a lot of people only consider Ultra Magnus to be "Ultra Magnus" if he has the trailer-armour, but that's a bias that's born from the G1 comics/cartoon which always showed him in his super-robot form... but as far as the toy is concerned the white cab robot is Ultra Magnus' true robot mode... the armoured mode is his super mode... something which Dreamwave comics portrayed (which I thought was kewl).

This is just _my_ personal opinion of what counts as C6/junker or not. I can perfectly understand it if other people would never count a trailer-less G1 Magnus.