The only 1871 f I have a list for is 1871 f 13 and that has all Scottish sheets and the datable ones are 1820-1830s. I've had a quick look through the list which has titles and first lines and can't see anything that looks like Bonny Boy. There are other 1871 f books such as f3 but I haven't got a list for that. Steve Roud has done more listing than I have and we usually exchange lists as we do them, but he has been moving house for the last few months and may not have any new info.

I'll use the first line and check the list thoroughly then I'll try the BL catalogue.

Woah, lad! Found it. I only had time to copy out the first stanza. It is 1871 f 13 60a if you want to send for it. The title is 'My Bonnie Laddie's Young'. SBG's first line is wrong.

Here it is as I copied it.
The trees they are high and the leaves are green
The days they are awa that you and I have seen
The cauld winter nights I maun lie my lane,
My bonnie laddie's young but he is growing.

There are as you have above 7 sts but how accurately SBG published them I don't currently know.

On the version itself I have a few comments. Firstly our old friend Peter Buchan was printing in Aberdeen around that time and he, like SBG, was quite fond of mixing and matching. That stanza 6 comes from at least 2 different ballads. For the first line see Christie Vol 2, p230, or Ord p179. There are 5 versions in Greig Duncan. The line given here occurs at the start of a version in Journal of the EFDSS Vol 4 No5. 1944 titled 'It happened on a day' sung by James Grant. The song does have some stanzas in common with Bonny Boy but the tune I have heard is different. The 3rd line I have a vague memory of from some other ballad. Does this st occur in any other versions?