Parksider here…
Rochester NY transplant from PA farm country. Been butchering and processing animals for years. I don’t like hunting, too cold… but I like the processing part so I found some friends that bring the venison, I bring the knowledge and tools: 3/4 hp grinder, 15# vertical stuffer, small vertical smoker, and a custom built 4x4x2 propane assisted smoker to process massive amounts of snack sticks-old PA dutch family recipe, Italian sausage, hot dogs.
I use lots of natural and collagen casings, like the bulk pack of small slim jim collagens are perfect. Typically run 100# batches of slim jims- cheese, no cheese, mild, hot… you name it we make it but always used base family recipe, worked for the first 100 years, good enough for me…
Do some BBQ, ribs and butts mostly. Getting into sous vide now to add a new angle.

Not sure of you dimensions but I used baking cooling racks, the have small “feet” of them to separate. I typically rotate them every hour or so. Can find them anywhere, walmart, target, and amazon. I have a restaurant supply house here in Rochester where I got mine originally. I actually had to cut mine down to fit the smoker, no problem with an angle grinder.

Re: How do you get sheep casings on a stuffer tube?
I was trained old school style but it works… after rinse and soak…fill stuffer and push a small bump of meat out of the tube aka “turtle head” cut the casing to get a clean straight end, leave the casing in a small bowl of water at the end of the tube. get some water into the casing and pull out of the water and onto the tube, keep the tube wet is the key and they should fly right on. I’ve never used veg oil but I could see how that would work.