The version below was collected from William Randall of Hursley, Hampshire by Dr. George Gardiner in June 1905 (Roud 1400). The tune was collected from Henry Norris of Farnham again by Gardiner in 1909 and it appears in Frank Purslow's book Wanton Seed.
I recorded way back in 1974? on Forest Tracks - Folk Songs from Hampshire, now re-released on CD.
You can even hear the track from the Cd at the link below (Sorry I can't seem to create Blue Clicky things!!)
http://www.forest-tracks.co.uk/folk_music_pages/folk_music_Hantstracks.html

Tim Radford

THE COUNTRY CARRIER.
I am a Country Carrier and a jovial soul am I
I whistle & sing from morn til night & troubles I'll defy,
I've one who bears my company & of work she does her share,
She not my wife upon my life
She my rattling old Bay Mare.
Chorus:
Then round goes the wheels
And trouble I'll defy
It's jogging al;ong together my boys
Me rattlling mare & I.

It's up & down the countryside my mare & I do go
The folks they kindly greet us as we journey to & fro
The cildren they all cheer & the old ones stop & stare
They lift their eyes with great surprise
To Joe & his old bay mare

Now when the loads are heavy & she's trolling up the hill,
I by her side assist her she works with such good will
She knows I love her well because the whip I spare
I would rather hurt myself than hurt
my rattling old bay mare.

Now when the town we reaches & she clatters over the stones
She lifts her hoofs so splendidly, she's not one of your lazy drones.
So clear the road for Joseph comes
You crawlers all take care,
With a driver smart a carriers cart,
It's Joe & his old bay mare.

I would not change my station for the noblest in the land,
I would not be Prime Minister or anything so grand.
I would not be an alderman to live in luxury
There's not an estate would separate
My rattling mare and me. (or I)