I'm not sure if you have the old pump or the patience to tinker but I suspect MAF cleaner to the inside, coupled with reverse flow and some **momentary** reverse polarity battery connects could free it.
Basically once the sediment jammed in there it stuck the rotor. Solvent, backflow under 60 psi, coupled with motor start in reverse and it may dislodge chunks.
That said the stalled motor may have been permanently damaged. But for 10" of tinkering you might see if it can be brought back to life....
