Had not used my Brownells manganese park solution in a while, skimmed the instructions, and proceeded to park some NDS AK receivers at around 155 degrees instead of the correct 190 degrees....lots of flock deposits, have not cleaned them up yet to see how they look under the crud areas...came out nice and dark where the flock didn't appear.

Any thoughts on if this would be OK or not?  Planned to paint these anyhow so not concerned too much about looks...  Dumb move but not wanting to re-blast them and have the lettering be unreadable....

That's up to you.  Should be OK, since you're coating anyway.  You could lightly blast it off and start over.  If you're careful around the lettering, it shouldn't effect it that much.  

I now regularly coat right over fresh, bare metal and it works just fine.  The purists will insist on park or anodizing first but meh.  Unless you are in an extreme humidity/salt water environment you'll be fine.