If you're restricted solely to image searches via the internet then you're always going to struggle. The terms you're using are also quite broad and will result in a kind of splattergun effect in which you might find what you're looking for but then again you might not. Whilst your ideas about equestrian gloves might bear fruit I'd doubt it. These are almost certainly British Driving gloves from the 1970s. My parents and grandparents all wore gloves just like these for driving and I'd allow myself a higher than 95% chance that that is what they are. If I were researching this, which I'm not, I'd concentrate on disambiguation and in order to do that I'd start with researching who made and sold these kinds of gloves in Britain in the 1960s and 1970s. To start you off you'll find 'Fownes', 'Dents', 'Chester Jefferies', and 'Marks and Spencer' should give you some ideas (there'll be lots more, trust me). Once you've started to narrow it down a bit you'll find something close and then you'll get closer etc.
I mentioned 'Fownes GT Gloves' because I've seen a few sets over the years in charity shops, jumble and car boot sales whilst looking for other items and can't overstate that if you really want to find stuff you're going to need to get out there. I'd always been struck by how much the Fownes gloves resembled these Han ANH gloves. I couldn't say if I've seen a set that were exactly the same because I wasn't really paying attention as this item doesn't really interest me. Purely for the benefit of this thread I did a little ebay dig to see if I could find a pair and then I simply purchased the first pair I found; I'll also add that you're also going to find it hard to advance unless you're prepared to take a punt on few things. Obviously this pair are the wrong colour and some details are not the same, which may be accounted for by these being for ladies, but I think you'll find the resemblance quite striking. Either way you definitely know that at least one company made gloves that are very close to what you are looking for.
Live the dream
Andy
http://i849.photobucket.com/albums/ab52/intwenothor/Real found parts/IMG_0645_zpsekzmyqba.jpg