I want to "glue" a military name tape to a nylon rifle scabbard. The scabbard has hard inserts on the side, so I can't get it into the wife's sewing machine. Can you recommend an adhesive that will hold up?

I used shoo goo in a similar application, and it’s been good for several years now

I've used this for a lot of projects. It works for tailoring pant inseam length and gluing fabric for upholstery repairs. If I am reading your post correct you are gluing fabric to fabric? You do need a steam iron to activate it.

You might consider contact cement. Apply thin layers to both surfaces, let dry, then press two pieces together.

I have used a fabric glue for similar projects that I got at Hobby Lobby.

I've used this for similar jobs. Surprisingly strong, yet flexible, and paintable it turns out.

 
Barge (yellow can only) is a contact cement that will hold anything to anything (just about). It is used extensively by saddlemakers and leather workers.
 

Loctite fan here with same results.

Amazing Goop.

http://eclecticproducts.com/products/e6000.html

E6000. Love this stuff. Plastic, paper, cloth, leather, metal... E6000 don't care. It's the honey badger of glues.

Rhino glue, make sure you choose a glue that is flexible after it dries.

Thank you all for your suggestions!