Could someone provide me with an ID and where I should pin?

I hope the photo is good enough. I’m taking an entomology course for school and we need to curate a collection of 50 insects and was able to find this guy already dead.

Unfortunately the info provided by my TA doesn’t really tell me where to pin for these kinds of cockroach where the wings (?) aren’t visible.

Now that I think about it, this might be a nymph from what I’ve read online. In that case should I just encase it in a vial of ethanol or can I still pin it?