“it’s the put-er-on-er-er”

It a quick and dirty way of adding emphasis to what you are saying. Like italicizing ing ing (that would be looking at something slanted three time normal italics) or Underling ing ing (Word with three lines under it) Have you got that all straightened out better-er-er now?

There are a couple of videos at YouTube, both American - the pants-put-er-on-er, and the armor-put-er-on-er, and a few Google hits for taker-off-er. A single 'er' after the preposition makes some sense, but I think the double 'er' was maybe a local variation.

There's also a zipper-up-er, and there's one of these with a double er on Facebook. Others in Google - 'bringer downer', 'setter upper', 'putter downer'. It's just another example of how people, especially children, like to play with language.

There are lots words we use in informal speech we don't use in formal writing. I see no reason not to use them in conversational emails, but they tend to lend themselves more to speech than writing. Some of them are in the dictionary, some not - a thingy, a thingumajig, a whatsit, a whatchacallit, a doodah. There's also a doofah, which I've just seen listed as being similar to thingy, i.e. when you can't remember something's name, but in Scotland at least, it was short for 'do for later', for example a cigarette you put behind your ear 'for later'.

Is it real English? Well the fact that some people say it and other people understand it, and it's not localised to one small group suggests it is real English, if not exactly Standard English (I doubt you'll find it in any dictionary). Is slang real English? I would say of course yes.

I can't find anything at Google Books, so I doubt you'll find this particular structure in grammar books, but I'm sure you'll be able to find something about made-up words like this, and especially how people like to play with words.

I've always liked 'dubry' or maybe 'doobry' for a thingamajig. Possibly derived from dewberry.

By golly there IS such a thing as a "pants-putter-downer" on YouTube!
https://www.youtube.com/embed/BDQ0UUZ0k50

@Liverwort - Oh, ye of little faith! :) And here's the one for armor-putter-on-er, with multiple '-er's. - http://www.youtube.com/watch?v=EsXZjZL5UrA

I suggest we make a collection of these thingies here:

do-er up-er - mainly Oz and NZ by the look of it - a house (or other thing) that needs doing up
- http://www.google.com/search?hl=en&q=do-upper#hl=en&q=%22do-er-up-er%22

The Marysville Gazette was talking about a "pick-er up- er and pull-er down-er" in 1955, but what it is, I have no idea.

The following each have several Google hits:
throw-er-away-er
break-er-up-er
pick-er-up-er
doer-without-er
talker-downer
jumper-talker-downer (or ledge-talker-downer)
(nose-)looker-downer

You certainly seem to have found a common pattern here, jayles, so I think we can definitely say it's English.

More at:
literalminded.wordpress.com/2010/03/02/picker-uppers-and-putter-upper-withers/

google "putter-upper"
"by-stander" and "passer-by" lack the -er on the adverb.

stl.recherche.univ-lille3.fr/sitespersonnels/cappelle/Pdf%20versions%20of%20papers/Doubler-upper%20nouns.pdf

OED has “picker-upper” (1913), “fixer-upper” (1932), “pepper-upper” (1934), “maker-upper” (1936), “builder-upper” (1936), “opener-upper” (1941), “mucker-upper” (1942), and “looker-upper” (1951). But “Ver-up” is actually more frequently attested than “Ver-upper” in the forms collected by the OED.

ablauttime.blogspot.co.nz/2004/09/passers-by-be-damned.html

http://en.wiktionary.org/wiki/fixer-upper

books.google.com/books?isbn=0071428933
books.google.com/books?isbn=1419535722

en.wiktionary.org/wiki/washer-upper

www.definition-of.com/bad+breaker-upper

@jayles - it's in the OED - so there's your answer. I notice these are all from 'up'. (well done,by the way, I hadn't thought of doubling the p in up), so how about with some other prepositions?

@WW "putter-onner" , putter-inner, taker-outer, leaver-outer, - all several have hits on google

urbandictionary.com/define.php?term=leader-onner
urbandictionary.com/define.php?term=picker-onner
urbandictionary.com/define.php?term=checker-upper-onner
urbandictionary.com/define.php?term=Awayer
www.urbandictionary.com/define.php?term=pusher-awayer

dictionary.reference.com/browse/warmerupper
dictionary.reference.com/browse/cheererupper

Curious how looker(s)-on was overtaken by onlooker(s) toward the end of 19th year-hundred.
Also the difference in meaning between passers-by and by-passers (ie people who take the bypass), and the following:
urbandictionary.com/define.php?term=holder-upper
http://en.wiktionary.org/wiki/upholder

I remember hearing "looker-after-er". Gives me 18,000 hits on Google.