Marty disclaims: None of which answers your questions.

au contraire, mon ami, the photograph (the horse on the right in the furrow) does explain the 'right' part of the definition (if it is typical). and the Robbie Burns connection is brilliant! the alternate spelling, furr-ahin, googled me this Robbie Burns poem:

The Inventory^1 In answer to a mandate by the Surveyor of the Taxes

Sir, as your mandate did request,I send you here a faithfu' list,
O' gudes an' gear, an' a' my graith,To which I'm clear to gi'e my aith.
Imprimis, then, for carriage cattle,I hae four brutes o' gallant mettle,
As ever drew afore a pettle.My hand-afore 's a guid auld has-been,
An' wight an' wilfu' a' his days been:My hand-ahin 's a weel gaun fillie,
That aft has borne me hame frae Killie.^2An' your auld borough mony a time
In days when riding was nae crime.But ance, when in my wooing pride
I, like a blockhead, boost to ride,The wilfu' creature sae I pat to,
(Lord pardon a' my sins, an' that too!)I play'd my fillie sic a shavie,
She's a' bedevil'd wi' the spavie.My furr-ahin 's a wordy beast,
As e'er in tug or tow was traced.The fourth's a Highland Donald hastle,
A damn'd red-wud Kilburnie blastie!Foreby a cowt, o' cowts the wale,
As ever ran afore a tail:Gin he be spar'd to be a beast,
He'll draw me fifteen pund at least.Wheel-carriages I ha'e but few,
Three carts, an' twa are feckly new;An auld wheelbarrow, mair for token,
Ae leg an' baith the trams are broken;I made a poker o' the spin'le,
An' my auld mither brunt the trin'le.
[Footnote 1: The "Inventory" was addressed to Mr. Aitken of Ayr, surveyor of
taxes for the district.]
---
so, a careful perusal <g> gives us 1) hand-afore 2) hand-ahin 3) furr-ahin and 4) ?furr-afore? for his four-brute team.

anyway, the question I had (the left-hand hindmost) would be the handahin, n'est-ce pas?