Looking at my first retro build.

I have my parts list ready to go but cannot find the upper I would like.
I like the look of the A1 receiver with the tear drop forward assist but without the shell deflector.  I don't know what it's called. All I can find is the A1 without the forward assist.
I think it's called a slick slide?

I'm learning that building a retro is not so much about building a rifle but learning about the amazing history of this weapon.

Any ideas?

Thanks for any help.

No one is making a new A1 upper receiver at the moment.

So you will have to find a good used one.

Look on the EE here, or on a auction site such as Gun Broker

Check the EE or gunbroker. You can usually find used ones. I don't know of any new manufacture.