Just digging through the archive & came across this thread...I'm quite interested in these sort of anomalies.
Different-sized records: you can pretty much have anything you want. Youtube has some footage of the White Stripes now very expensive doll's house-size ones from a few years back. I've got many 3"CDs, at least one 5" vinyl record (C*ck ESP Vs Evil Moisture), 6" flexis, 7", 8" (78s & lathes, I think), 9" (NIN), 10", 11" (Alien Sex Fiend) & 12" records, shaped (including shaped CDs - theres a Flaming Lips single & I think some others too), picture discs, coloured vinyl...
I was also always kinda fond of those records that are normal sized but have weirdly balanced use of the space too...ie; you get some 78s with tiny little labels & grooves right up to them, then theres the 10"-pressed-onto-a-12" thing which seemed popular for early jungle stuff, & recently you've had a bunch of Spanish rave stuff on 12" with massive labels & die-cut sleeves designed to show them off...
Then theres the weird grooves...concentrics were mentioned...theres also ones where the record has been cut so the needle glides over the vinyl during the music...one called "Stylus Flight" by Equitek on R&S is particularly pronounced (& a great record).
Locked grooves - theres even more records just featuring these than I previously thought. The Non one mentioned with the offset centre has some on, theres the RRR100 & RRR500 classics, a Stock Hausen & Walkman 7" (a bit throwaway), loads of dance music ones...type 'lock groove' or 'locked groove' into discogs & you get loads.
The reggae records with radio playing through them MIGHT be reused vinyl...I've heard about existing records being cut into again & some of the previous record playing through...I think thats more people making their own lathe cuts though...
Finally (for the moment), I'm quite interested in playable etchings, of which there are very few that I know of...its kinda a noise thing....this probably started with the Savage Pencil one on that Lee Ranaldo album, but theres also one on Wolf Eyes "F*** the Old Miami" (the record is stamped over the etching or vice versa, so its music not noise created by the etching...it DOES play through, despite what people might tell you) & Emil Beaulieu's "Greatest American Noise Artist" (or whatever its called) opens a couple of sides with an etching that looks like a nail was used to make scratches into the master...needle just kinda goes RRRrrrHHHHHHRRrrrTtt & then settles into the next track!!
