Slings to carry medieval crossbows?

I want to come up with a way to sling my crossbow for SCA combat.

My thoughts are to run a cord or thong through the binding hole of the cross bow and attach a large D ring to it. Lash another D ring near the butt. Hook ends of a strap to my armor about the same place my shoulder straps on my weapon side attach. Running loosely through the rings the strap would hopefully allow me to move the crossbow enough to load and shoot while allowing me to 'drop it' to throw hammers or work a ballista.

I don't want the strap running around my neck so I don't get strangled in some sort of press / mound of bodies.

Has anyone else experimented with crossbow slings? Other option for the butt of the crossbow is to copy the butt sling attachment of a Mauser 98.

How about a sling fixed firmly to the crossbow and attached to rings on my armor?

I have to imagine a crossbowman of old had some way of slinging a crossbow on the march. Did they use some sort of case or bag to protect it in nasty weather? Any ideas?

About the carrier for a crossbow...how about a club hammer bracket on a belt (the sort of thing bricklayers and builders use) or make something similar to slot the main body of the crossbow into?

I haven't got an answer for you, but I'm interested in whatever solution you come up with, as I've been pondering a carry method myself. I think, historically, military crossbowmen did just carry them. It would have been their primary weapon, and they probably would have had whatever else they needed hanging from their backs and shoulders. In fantasy art and games I often see crossbows strapped on the back with the prod up, parallel to the shoulders. I tried that and it doesn't work as good as it looks. For one thing, the prod end is the heavy end and it has to be really secure to keep from riding down, and if it's that secure your buck or your enemy Larper or your zombie is going to be long gone by the time you shake it loose. I found for my rifle-stock crossbows that a prod-down position is much more comfortable, with the stock flat against my back and the prod at my side under my arm. I have yet to take any long hikes in the bush to see how well this works out in the field, though.

I have a sling on mine because I hunt with it on occasion. I carry mine prod down even though it has a fiberglass prod which is a lot lighter. It goes through the brush easier that way. I have an 1 1/2 inch wide leather strap that I used a Chicago screw to attach around the foot stirrup and a Windsor knot on the other end. The Windsor knot allows it to be some what adjustable and applies enough pressure if you tie it tight not to slip.

Geezer here: Slings for crossbows... there's a puzzler. There are some 15th century drawings of mounted Swiss crossbowmen, with their bows attached to their saddles... often in cases that cover the prod and stock back to the lock only. Searching in the Osprey Men at Arms series may turn those up. Osprey uses lots of period illustrations for their books, and those illos may be accurate as far as the original artist knew. Their full-color plate interpretations are often much less accurate, at least as far as crossbows are concerned.
The very small nose-ring that one sees on both Padre Island bows, and lots of the short, fat Germanic horse-bows (like my model 5B) are almost certainly provided for hanging up the bow.
The original Maximilian I bow, as seen in the Hofburg in Vienna, has a flat metal hook on the bottom of the stock, just behind the prod. It looks very much like a flattend bolt-clip, mounted so it can't swivel. That's GOT to be a hanging-hook, but whether it's intended for the wall or a saddle, or belt, I don't know. I think the Maximilian bows in the Hofburg would be too long to hang from a waist-belt unless Old Max was Very-very tall indeed.
As far as practicalities are concerned, I find it easier to carry a crossbow through the woods with the prod held fore/aft, rather than across. Consider that there are plenty of crossbow-prods out there over 30 inches wide... probably wider than most archers' shoulders. So yeah, orient the prod fore and aft, and if you put the prod on your shoulder and you hit something, it's liable to twist around and hit you in the eye... so I think waist level would be safer.
When carrying spanned, ready to shoot, you would need to keep the limbs more or less level unless your bolt-clip was very tight... or carry the bow spanned but un-loaded until you see your target.
Just thinkin' Geezer.

One approach, certainly not histrical but effective, is the slings that blackpowder hunters sometimes create for Hawkins / Plains rifles, trade guns, and so on. Those weapons were never equipped with sling swivels, but I've seen them made all of leather, with a kind of boot at one end for the butt. Dixie Gun Works carries this kind of product. Maybe you can get inspiration to create some sort of workable sling.

Dane