Suggestion for next episode: the promo blimps.

Cool episode... though you missed the holiest grail; at least one stock copy of the Japanese 'Immigrant Song' exists.

The rarest mistakes are when one side of the record is from an entirely different release. This 90's release of Houses has a Green Day record on one side and supposedly sold for over $1000: htps://www.discogs.com/Green-Day-Led-Zeppelin-Dookie-Houses-Of-The-Holy/release/7184799 The price seems way out of line but all it takes is one looney.

I think the most prized misprint is the few pressings of the Irish edition of the 4th LP that had Asylum labels: https://www.discogs.com/Led-Zeppelin-Untitled/release/6420213 There was also the Turkish sleeve for the Immigrant Song with a misspelled title: https://www.discogs.com/Led-Zeppelin-Immigrant-Song-Hey-Hey-What-Can-I-Do/release/4520637 Allegedly when they realized the mistake they just pulled the sleeve and didn't release a corrected version.

For an official Atlantic issue, that is probably the record. There are some Taiwanese and Korean pirates that completely butcher the English language.

Those types of errors are uncommon, but not particularly valued. There would be a premium of, I'd say, 50% at most.

I don't know who started selling these "15½" master reels" but they made a killing selling what I assume are needledrops. http://www.valueyourmusic.com/reel-to-reel?utf8=✓&q=led+zeppelin+15

This one actually looks like it could be real: https://www.popsike.com/LED-ZEPPELIN-1969-promo-MEXICAN-7-unique-FREE-SHIPP-jimmy-page-yardbirds/352919807336.html

There are a bunch of other Mexican 'promos' out there: https://www.popsike.com/php/quicksearch.php?searchtext=zeppelin+mexican+promo&layout=&sortord=adate&endfrom=&endthru=#

This 'promo from Uruguay' is supposedly from 1972, but the cover picture is from the 1977 tour. Also it seems a single seller managed to find about 15 of them and started listing them on ebay in 2015... https://www.discogs.com/sell/item/1066351903?utm_campaign=sell_email_new&utm_medium=pm&format=Vinyl&text=Led-Zeppelin-Friends-Celebration-Days&ev=wh_new&utm_source=relationship

This one seller seems to have found a trove of Russian records pressed clandestinely on old x-ray film. I remember seeing articles about these, but only jazz records from the 40's and 50's. If these were legit, you would think more than one single seller would have found them. https://www.popsike.com/php/quicksearch.php?searchtext=russian+x-ray&sortord=adate&pagenum=1&incldescr=&layout=&sprice=&eprice=&endfrom=&endthru=&bidsfrom=&bidsthru=

I just saw this auction on Ebay: https://www.ebay.com/itm/LED-ZEPPELIN-Led-Zeppelin-IV-1972-MEXICO-ADVANCE-PROMO-7-EP-Psych-33rpm/174202714256?hash=item288f4a7890%3Ag%3AK0QAAOSw7BleVjPX&LH_Auction=1 If it were real, it would be a very cool item to have, but there are too many red flags. I have noticed a lot of these fantasy items for sale lately, so I am going to post a few in this thread, in hopes of preventing you guys from getting ripped off.

Ebay is a great platform for long-time reputable sellers who have built a strong following. If you are a first-time seller, you likely will get ignored because unfortunately there are a LOT of charlatans out there, and a test pressing is easy to fake. I suggest you find someone knowledgeable about these things to check it out first. Tell us where you are and I'm sure someone here can suggest some names.

If you're saying your record has labels for side 1 on both sides, it's no big deal. You might get a slight premium if you resell it.

I think that red disc was exclusive to Japan and not widely distributed elsewhere.