I love this song! Here's my best guess at lyrics, Andy M Stewart-style:

One Sunday morn as I rode out
with the road bein' dark and dusty-oh,
well a friend and I stepped into an inn
for a horn o' Jenny Grey's whiskey-oh.

CHORUS:
Of her gin she keeps the royal blue
and the best of all Scots whiskey too,
No cordial cure is half so pure
as a horn o' Jenny Grey's whiskey-oh.

Now there's some that likes tae quarrel and bite
whenever they get tipsy-oh,
ah but gie me a lass and full flowin' glass
filled up with a horn o' whiskey-oh.

So come all ye misers great and small
for your gold is gettin' dusty-oh,
don't sit and think but come and drink
of a horn o' Jenny Grey's whiskey-oh.

One Sunday morn as I rode out
with the road bein' dark and dusty-oh,
well a friend and I stepped into an inn
for a horn o' Jenny Grey's whiskey-oh.

-- I once tried to look up and see what gin might have been the "royal blue," but I ended up reading someplace that, customarily, gin labels were dark blue. I can't find any reference to that now, though, and it was off the 'net so take it with a grain of salt.