This is one of those songs that can be found in a great many variant forms.  Francis Child (English and Scottish Popular Ballads) assigned to it his number #279, but allowed other, apparantly related, songs in at #280.  I haven't, so far as I can remember, heard Isla StClair's recording, so I don't know which of many traditional versions she used.  As a rule, I suggest that people try a search for themselves through the "Digitrad and Forum Search" facility on the main Forum page before starting a new thread, but in this case you'd have found that quite difficult to do, as the song is more usually known by other titles.  Here is a list of links which you may find useful:

In the DT (Digital Tradition database):

THE BEGGAR LADDIE  From Folk Songs and Ballads of Scotland, MacColl, with tune.  Wrongly labelled Child #200
THE BEGGAR MAN (2)  As recorded by by Cilla Fisher and Artie Tresize; no original source named or tune given.
THE BEGGAR MAN (4)  Collation, with tune,made from several different traditional and printed versions.  (Stephen Sedley, The Seeds of Love, 1967).
THE JOLLY BEGGAR   Described as "from Sedley, Seeds of Love", the text is nothing of the kind, and appears to be an incomplete transcription from a Planxty record.  Certainly it's the tune they used, which does come from Sedley, and is a Scottish one described by Sedley as "the best known of the Scots melodies", though unfortunately he didn't say where he got it.
THE BEGGARMAN (3)  As recorded by Richard Dyer Bennet, no source named: with tune.
THE BEGGARMAN (6)  No source named or tune given.

In the Forum:

The Gabalundi(?) Man  The text that "davebhoy" has copied-and-pasted comes from this thread.  It was taken from Ewan MacColl's book Folk Songs & Ballads of Scotland.
Beggarman  A discussion of no importance except for this comment from Bruce Olson.
The Jolly Beggerman  Includes 3 texts; (1) quote from a set recorded by Ewan MacColl, (2) transcription from that Planxty record, (3) unattributed "Scottish version".

Entries at the  Traditional Ballad Index:

The Gaberlunzie Man, [Child 279A]
The Jolly Beggar, [Child 279]

See also:

The Beggar-Laddie, [Child 280]

At  Lesley Nelson's   site:

The Gaberlunzie Man with tune; this is the set printed as an appendix to #279 by Child, quoted from (ulimately) Ramsay's Tea-Table Miscellany of 1724.
Child texts  The two texts given by Child, plus the expurgated The Pollittick Begger-Man
Hi for the Beggar Man With tune; no source given.

At Bruce Olson's site;  Roots of Folk: Old English, Scots, and Irish Songs and Tunes:

The Pollitick Begger-Man. (unexpurgated version)

At the  Bodleian Library Broadside Collection:

The beggar man Printer and date unknown
The jolly beggar Printer and date unknown
The jolly beggar Printed between 1774 and 1825 by Angus of Newcastle.

There are a number of other versions available in print and on record, even more if you count "covers" of traditional sets recorded by Revival singers.  The big question is, are any of these close to what you were looking for?

A wee plea of my own, now, aimed at everybody; please, when answering a request for song lyrics, DON'T COPY LYRICS FROM OTHER THREADS.  Threads are not deleted here, and remain in the permanent archive; this means that, the next time someone asks about this song, there will be another duplicated set of lyrics which will have to be checked.  It just makes everybody's life a little more difficult than it needs to be.  The best thing you can do is put in a link to the lyrics you've found, or, if you don't know how to do that, just copy-and-paste the URL.  Davebhoy lost the original formatting when pasting, of course; have a look at the FAQ at the top of the Threads list on the main Forum page for useful information on how to post lyrics so that doesn't happen.

I don't for a moment want to discourage anyone from helping out, but I do want them to do it in the most helpful way possible; one that doesn't make it harder for other people to help later on.

Malcolm