If Liam is correct that, "A body is a body really, they all work." then the cheapest entry full manual with aperture priority and TTL flash is the Nikon FG
I assume you wanted the Nikon FA because it is the most feature rich manual focus Nikon body. No other manual focus Nikon body has all this.
Your Pentax must have been broken as I have a range of Pentax from 1957 to 1983 and have not seen such a thing. For that matter, I am certain I have never seen an off-center viewfinder in any of the cameras I have.
Originally Posted by HTF III