Looking for options on a No drill sling for my 45-70 Marlin. I see some that are simple loops on both ends, but never have tried them. Don’t want to drill my wood. Any suggestions?

Those loop type slings all look like they didn't belong there, although they work for carrying. So will a piece of rope.
Drill it.

I saw those and like the concept. Was thinking about something that could be easily removed once in the stand. That one appears to have a swivel at the forearm.

You can't drill a Marlin forearm for a swivel; way too thin. Most of these clamp onto the magazine tube. Or you can drill into the forearm cap and install a swivel or stud there.
Just drill the buttstock and screw in a stud.

I found this inexpensive rifle cover with a sling and ordered it. Hope this fits my needs.

https://www.sarcoinc.com/lee-e.../#product-reviews-mn