I've been doing a bit of searching on the Sothebys auction archive over the past couple of months and, while there aren't lots of SYW-related items, it does seem to throw up the odd really interesting piece now and again. I'm a bit wary of uploading lots of pictures from their site, as I'm not sure of how the image rights work with recently sold paintings, but a few seemed too useful or interesting not to share.
'Cavalry Party at Rest by the side of a Road' by Jean-Baptiste Le Paon
This first image is a period image of either British or Hanoverian cavalry at rest (I think but would be happy to be corrected) and seems to be a quite useful depiction of the uniforms and horse furniture of whichever units these men are from.
'An officer relieving a sick soldier' by Edward Penny
Look familiar? This stood out immediately to me, as it is essentially the same painting as Penny's famous depiction of Granby, but with Granby replaced by an officer of the 3rd Irish Horse.
'Two Polychrome Painted Dummy Board Figures of an Ottoman Soldier and an Imperial Soldier'
This description comes from the Sothebys auction listing but I'm pretty certain the figure on the right is a Pandour not an Ottoman, due to the pistols, the cape, the clothes, the busby and the fact that he was painted as part of a set with an Austrian Grenadier. I'd say this is my favourite of the lot, I'd never seen figures like this and they are quite large (209 and 206 cm tall) and very detailed.
Unfortunately the site is not overflowing with items like these, just the odd bits and bobs that have come up for auction every now and then. It really makes you wonder how much stuff like this is tucked away out there in private collections that we don't know about. Then again, perhaps we do know about them and it's just me who's seeing something new.
If you wanted to have a look for things yourself go to this link and use the search box in the top right hand corner. Then, once the search results come back as 0, click the 'Sold Lot Archive' tag in the middle of the page. A word of advice if you do decide to have a look; don't make your searches too specific unless you know the name of an artist. The two Imperial figures were found with the search term '18th soldier', with the 18th being for the century (if you put '18th century' it won't throw up items that have '18th and 19th centuries' for example). Image quality can also vary considerably, with the older auctions being especially blurred.
Also, I'm having luck on the painting front and seem to have hit my stride. I should have a unit of American Rangers painted and based by the end of the month. Fingers crossed.