I bought this a while back, but don't know enough about reproduction port doors to make a decision myself. Its obviously been refinished/painted. Any help would be appreciated.

Looks good to me.

it's worn nice, but I do believe that is a repro. You can tell by how defined the raised ridge is.

https://www.ar15.com/forums/t_3_123/697338_.html&page=1

It's real deal not repro IMO.  Repro's the corners of seam / raised ridge are almost squared off and not as rounded or the biggest visible difference on one's I have anyway.  Latch looks USGI and not repro either way it's staked. Strip it or use naval jelly and see what it looks like underneath.  Doesn't appear to be pitted or anything.  Hit it with grey dry film lube and don't look back if finish is trashed.