Here is what I could glean from Vol 5 of THE ENGLISH AND SCOTTISH POPULAR BALLADS (Dover) with regard to ballads from the 1700s collected by Child. I have included all of the Appendices, etc. Again, please forgive gross errors and misunderstandings since I am totally unfamiliar with Child's sources. At the end of all of this, I did find Child's "Sources Of The Texts of the English and Scottish Ballads", which was very helpful and if I had the energy, I should go back over everything and double check it with this list in hand, but for now..."
JOHN THOMSON AND THE TURK—B
Leyden's Glossary to The Complaynt of Scotland, p. 371. ["Leyden (1801) says that he had "heard the whole song when very young."]
THE HEIR OF LINNE—A
Percy MS., p. 71; Hales and Furnivall, I, 174. [1765, 1794]
And, "THE RUNKARD'S LEGACY" from Percy's Papers in Appendix
THE LORD OF LORN AND THE FALSE STEWARD—A
Percy MS., p. 73, Hales and Furnivall, I, 180.
THE LORD OF LORN AND THE FALSE STEWARD—B
Wood, 401, fol. 95 b. b. Roxburghe, I, 222, III, 534; Roxburghe Ballads, ed. Chappell, II, 55. c. Pepys, I, 494, No 254 (from a transcript in Percy's p
THE SUFFOLK MIRACLE
Wood, E. 25, fol. 83. b. Roxburghe, II, 240; Moore's Pictorial Book of Ancient Ballad Poetry, p. 463. [also Pepys,III...Old Ballads, 1723]
KING EDWARD THE FOURTH AND A TANNER OF TAMWORTH
a. Wood, 401, fol. 44, Bodleian Library.
b. Douce, I, 109, Bodleian Library.
Roxburghe, I, 176, 177; Chappell, Roxburghe Ballads, I, 529.
And "KING HENRY II AND THE MILLER OF MANSFIELD in Percy
Herd's MSS, I, 140. 
A broadside: Printed and Sold at the Printing-Office in Bow Church-Yard, London.
GET UP AND BAR THE DOOR—A
Herd, The Ancient and Modern Scots Songs, 1769, p. 330. b. [Pinkerton], Select Scotish Ballads, 1783, II, 150.
GET UP AND BAR THE DOOR—C
Johnson's Museum, IV, 376, No 365, 1792. Contributed by Robert Burns.
THE FRIAR IN THE WELL—A
a. Rawlinson, 566, fol. 63, 40. b. Roxburghe, II, 172; Ebsworth, Roxburghe Ballads, VII, 222. c. D'Urfey's Pills to purge Melancholy, ed. 1719, III, 325.
THE WIFE WRAPT IN WETHER'S SKIN—A
Jamieson's Popular Ballads, I, 319. "From the recitation of a friend of the editor's in Morayshire." [A fragment in Herd's MSS, I...belongs, if not to this ballad, at least to one in which an attempt is made to tame a shrew by castigation."]
THE JOLLY BEGGAR—B
a. Herd, The Ancient and Modern Scots Songs, 1769, p. 46. b. Curious Tracts, Scotland, British Museum, 1078, m. 24, No 30. ["The Gaberlunyie -Man" was, so far as can be ascertained, first printed in teh Tea-Table Miscellany (in 1724)...." Pinkerton 1783, Johnson, 1790, ritson 1794, Herd 1776]
THE CRAFTY FARMER
a. 'The Crafty Farmer,' Logan, A Pedlar's Pack, p. 126, from a chap-book of 1796; 'The Crafty Miller,' Maidment, Scotish Ballads and Songs, 1859, p. 208, from a Glasgow stall-copy; a stall-copy, printed by M. Randall, Stirling.
'The Yorkshire Farmer,' Kidson, Traditional Tunes, p.140, from The Manchester Songster, 1792.
Ravenscroft's Deuteromelia, London, 1609; No 1 of Freemen's Songs, sig. B.
THE GEORGE ALOE AND THE SWEEPSTAKE
a. Percy Papers, "from an ancient black-letter copy in Ballard's collection."
b. Rawlinson, 566, fol. 183, 40.
Roxburghe, III, 204, in Ebsworth, Roxburghe Ballads, VI, 408.
THE SWEET TRINITY (THE GOLDEN VANITY)—A
Pepys Ballads, IV, 196, No 189.
CAPTAIN WARD AND THE RAINBOW
Bagford Ballads, I, 65. [Pepys]
THE YOUNG EARL OF ESSEX'S VICTORY OVER THE EMPEROR OF GERMANY—A
Douce Ballads, III, fol. 80 b. b. Roxburghe, III, 416, in Ebsworth's Roxburghe Ballads, VI, 405. [in Evans's Old Ballads, 1777]
The Glasgow Lasses Garland, the second piece, British Museum, 11621. c. 3 (68). "Newcastle, 1765?"
JOHN OF HAZELGREEN—A
Elizabeth Cochrane's MS., p. 126. ["having been transcribed by C.K. Sharpe for Sir W. Scott "from a 4to MS., in a female hand, written probably about one hundred years ago,...."]
THE OUTLAW MURRAY—A
Herd's MSS, II, fol. 76, I, 255, 1795. b. Minstrelsy of the Scottish Border, 1803, I, 1; principally from a copy found among the papers of the late Mrs Cockburn, of Edinburgh. c. Aytoun's Ballads of Scotland, 1859, II, 131; "from an old manuscript in the Philiphaugh charterchest," now not accessible. d. A copy among the Philiphaugh papers, transcribed not earlier than 1848.
THE OUTLAW MURRAY—B
Glenriddell's MSS, XI, 61, 1791.
ADDITIONS & CORRECTIONS, etc
THE THREE RAVENS
a version from E. Peacock, Lincolnshire, "whose father, born in 1793, heard it as a boy at harvest suppers and sheep-shearings, and took down a copy from the recitation of Harry Richard, a laborer, who cold not read and had leart it 'from his fore-elders.'
Five Excellent New Songs. Edinburgh. Printed and sold by William Forrest, at the head of the Cowgate, 1766.
FAIR MARGARET AND SWEET WILLIAM
"Communicated by Miss Mary E. Burleigh, of Worcester MA, and deriaved, through a relative, from her great-grandmother, who had heard the ballad sung at gatherings of young people in Webster, MA, not long after 1820."
THE BAFFLED KNIGHT
The Complete Collection of Old and New English and Scotch Songs, 1735...repetitions from earlier publications;...."
THE WIFE WRAPT IN WETHER'S SKIN
"From the recitation of Miss Lydia R. Nichols, Salem, MA, as heard in the early years of this century. Sung by a New England country fellow on ship-board...."