Manky and mank are used pretty commonly in the US (and Canada, I think) by paddlers to refer to the smell of wet, unwashed paddling clothes and footwear. I think I’ve also heard manky used to describe dirty water, or stretches of water with lots of brush, nuisance rocks or the like.
Are "chunter" and "manky" Liverpool or Canadian slang words? And I'm not quite sure what they mean..
‘Plod’ means something more like ‘trudge’ than ‘trundle’ - there is an implication of moving forward wearily and slowly on foot (‘trundle’ implies wheels).
I imagine (but cannot prove) that PC Plod was so named because he’s a bobby with a beat that he patrols on foot.
Quite. Time was, Gray’s Elegy in a Country Churchyard was regularly learned by heart in English schools:
The ploughman homeward plods his weary way,
And leaves the world to darkness and to me
OED quotes sources back into the 16th century.
“Chunter” to me has always been to do with speech rather than movement. Something more than muttering, implicitly repetitive, often bearing some sense of grievance. I think the author quoted was using a bit of poetic licence, rather suggests they were playing whatever it was without much enthusiasm, going through the motions.
Yes, the OP made me think of that particular piece of Australian slang (and elsewhere?) It also made me think of the Scottish “haver.”
The Children’s Encyclopaedia, which was pitched at quite young children, quoted this line and explained how the words in that short sentence could be arranged in a huge number of different ways while still preserving the essential meaning. 
Goodness me, is that Arthur Mee’s Children’s Encyclopedia? I was brought up on that.
Mind, it was all fields round here in them days.
56 year-old Canadian here - I’ve never heard, or heard of, either of those words until I read the question here.
Chuntering is often associated with teenagers, when told by parents they cannot do or have something, they may whinge and complain and moan about the unfairness of everything - that is classic chuntering
Does no one here watch “American Pickers”? One of the guys (tall skinny one) regularly uses “manky” to describe the condition of some item he might be interested in.
Not sure how I forgot about this one:
[QUOTE=In Bruges]
Two manky hookers and a racist dwarf. I think I’m heading home.
[/QUOTE]