Here's the tune from Ord.

I've also notices a few minor textual differences between the linked text and Ord that I missed last night:

   v1, l3: haught Ord: haughty
   v3, l7: devoid of sin Ord: devoid o' sin
   Ch and last line of verses:
           working life oot Ord: working life out
  

Mick

---

I'M A WORKING CHAP

  I'm a/ work-ing chap as/ you may see, You'll/ find an hon-est/ lad in me;
  I'm/ neith-er haught-y,/ mean nor proud, Nor/ ev-er tak's the/ thing too rude.
  I/ nev-er gang a-/bune my means, Nor/ seek as-ssist-ance/ frae my frien's,
  But/ day and nicht thro'/ thick and thin, I'm/ work-in' life out to/ keep life in.//
   Chorus:
   Nae/ mait-ter, frien's, what-/e'er be-fa', The/ puir folks they maun/ work a-wa',   
   Through/ frost and snaw and/ rain and wind, They're/ work-ing life out to/ keep life in.//
  
  
  X: 1
  T:I'm A Working Chap
  M:6/8
  L:1/8
  S:Ord: Bothy Songs And Ballads
  K:C
  c/ B/|A2 A D2 D|F2 F G2 G|A2 A D2 F|E2 D C 
  (c/ B/)|A2 A D2 D|F2 F G2 G|A2 A D2 F|E2 D C 
  A|d2 d A2 A|d2 d A2 B|c2 c G2 G|c2 B A2
  A|d2 B c2 G|c2 B A2 A|G G G c2 B|A2 D D2||
  (c/ B/)|A2 A D2 D|F2 F G2 G|A2 A C2 C|E2 F G2
  A|d2 B c2 G|c2 B A2 A|G G G c2 B|A2 D D2||
  

Source:John Ord: Bothy Songs And Ballads