Is an FAA Form8130-3 with block 11 “Rebuilt” permissible for motor components, among other magnets?

No, as set out in the EASA-FAA bilateral agreement, only FAA Form8130-3 Rebuilt for engine are acceptable, as set out in point 10.11.1.6 “Engines rebuilt by the PAH can be accepted as specified in the TIP associated with Annex 1 of the Agreement.

“Rebuilt Engine” means an engine that has been disassembled, cleaned, inspected, repaired as necessary, reassembled, and tested to the same tolerances and limits as a new item by the production approval holder in 
accordance with 14 CFR part 43.