Triplett & Scott Question

[plymouthairrifle]

I have a Triplett & Scott with a 20" barrel. I have looked at a lot of photos and the guns with a 20" barrels have one sling swivel on the bottom of the stock. On 30" barrels there are swivels on the top and bottom of the stock. The swivels on the short and long barrel guns are also different. My question is; How did a sling attach and how was it used on these guns? There is no sling ring or bar on the receiver like many of the carbines had.