I'm not so sure about it being OK..... The varnish on the motor windings looks burnt and when / if moisture gets in there again, the green meanies will grow pretty quick. I think that "goop" is water soaked grease, or used to be, anyway.
I would just bite the bullet and get another motor. By the time it's all over and done with after aquiring new brushes, brush holders, re-insulating windings, replacing the bearings and getting an end plate to replace the BBQ'd one, you would have spent the same $$$$$$, plus a whole lot of time making repairs to a known bad motor. The risk of burning it up again and maybe it being worse of a "fire" is too great.
Those motors are all over the internet for under a hundred fifty. Piece of mind having "new" with a warrenty....
Oh yeah, hats off to a gal that doesn't mind getting dirt under her fingernails, especially a looker. Wish my other half was like that....