I can't find a recording either. Here are the words:

The Tunnocks Caramel Wafer (Adam McNaughtan)
Tune: The Barren Rocks of Aden

A hundred year an' mair's gone roon
Since Thomas Tunnock raised eighty poun'
An' proudly paid his money doon
To be a purveyor an' baker.
At weddin's, pic-nics an' soirees,
Wi' bags o' buns an' full high teas
Tom Tunnock showed his expertise
As Lanarkshire's pie-maker.
But little was he thinkin' as the dough he made
For the mutton pies an' tottie scones that he purveyed,
He was layin' the foundation o' a world-wide trade
In Tunnock's Caramel Wafers.

When the First World War was done,
Archie Tunnock, Thomas's son,
Came back hame to Uddingston,
Breid-winner o' the faim'ly.
Archie baked an' Archie planned,
An' he watched the company expand
To be the finest in the land
For wholesome food an' hamely.
Wi' a growin' reputation for traditional fare
An' a knowledge o' technology beyond compare,
Profits ploughed intae machinery a' helped prepare
For the Tunnock's Caramel Wafer.

The Saicont War brought mony a qualm:
Synthetic cream an' turnip jam
An' trifle bein' delivert by tram
Wherever they could send it.
But Archie Tunnock had a scheme
To match a sweet-toothed nation's dream,
A chocolate biscuit treat supreme
When the sugar rationin' endit.
Steyin' at the bakin' plate frae morn till night,
Mixin' caramel an' milk until he got it right;
In nineteen fifty-wan the world got its first bite
At a Tunnock's Caramel Wafer.

The rest o' the tale is easy told:
The distinctive foil of red and gold,
The vans that multiplied ten-fold,
Deliverin' Caramel Wafers.
Frae Motherwell to Martinique
Three million people every week,
Jew an' Arab, Turk an' Greek,
Agree on their favourite wafer.
But though the Caramel Wafer may be known world-wide,
It's always been in Uddingston that Tunnocks bide,
An' the firm an' the community and faim'ly's pride
Is the Tunnock's Caramel Wafer.