Here's the versions in my books. ROYAL CHARLIE
1.
When France had her assistance lent.
Our darling prince to us she sen t,
Towards the north his course he bent,
His name was Royal Charlie.
But O, he was lang o' coming,
O, he was lang o' coming,
O, he was lang o' coming:—
Welcome, Royal Charlie.

2.
When he upon the shore did stand,
The friends he had within the land
Came down and shook him by the hand,
And welcomed Royal Charlie.
Wi' "O, ye've been lang o' coming," etc.

3.
The dress that our Prince Charlie had
Was bonnet blue and tartan plaid;
And O he was a handsome lad!
Few could compare wi' Charlie.
But O, he was lang o' coming, etc.

— from G. S. Macquoid, Jacobite Songs and Ballads (London: Walter Scott, n.d.), p. 160. Very similar in the next source.

OH! HE'S BEEN LANG O' COMING

1.
The youth that should have been our king,
Was dress'd in yellow, red, and green,
A braver lad ye wadna seen,
Than our brave royal Charlie.
Oh! he's been lang o' coming,
Lang, lang, lang, o' coming,
Oh! he's been lang o' coming,
Welcome royal Charlie.

2.
At Falkirk, and at Prestonpans,
Supported by the Highland clans,
They broke the Hanoverian bands,
For our brave royal Charlie.
Oh! he's been lang, etc.

3.
The valiant chief, the brave Lochiel,
He met Prince Charlie on the dale;
Then, O! what kindness did prevail,
Between the Chief and Charlie.
Oh! he's been lang, etc.

4.
O come and quaff along wi' me,
And drink a bumper, three times three,
To him that's come to set us free,
Huzzy! rejoice for Charlie.
Oh! he's been lang, etc.

5.
We darena brew a peck o' maut,
But Geordie says it is a faut;
And to our kail cannot get saut,
For want of royal Charlie.
Oh! he's been lang, etc.

6.
Now our good king abroad is gone,
A German whelp now fills the throne,
And whelps it is denied by none,
Are brutes compared to Charlie.
Oh! he's been lang, etc.

7.
Now our good king is turn'd awa',
A German whelp now rules us a';
And tho' we're forc'd against our law,
The right belongs rto Charlie.
Oh! he's been lang, etc.

8.
If we had but our Charlie back,
We wadna fear the German's crack;
Wi' a' his thieving hungry pack,
The right belongs to Charlie.
Oh! he's been lang, etc.

9.
O, Charlie come and lead the way,
No German whelp shall bear the sway,
Tho' ilka dog maun hae his day;
The right belongs to Charlie.
Oh! he's been lang, etc.

— From Charles Mackay, The Jacobite Songs and Ballads of Scotland, from 1688 to 1746. (London-Glasgow: Griffin, 1861), pp. 232-4.
The references to "whelps" are not just ordinary insults, but scurrilous puns on the family name of the House of Hanover, "Guelph". George I is called "Geordie Whelps" in several places. The above was "rescued", as Mackay says, from oblivion by Peter Buchan, north-east folksong collector and printer (and accused of being too credulous and careless)—but Mackay thinks it is a genuine antique.