If it was mine, and they were not too busy at my former employer. It would be a perfect canidate for plastic media blast then do a glass bead blast. Rougher beads for steel iron products. If not that I've used evaporust with real good results. Get some small steel brushes a jug of Zep 505. Verystrong industrial degreaser, hot water. Hit hard for little while. Rinse, stuff it in the Evaporust overnight or longer check it once in while. Thats worked for oldtools from fleamarkets, other small restored parts. Good luck. You can now get 30% white vinegar. Before was only up to 5 to 8%. It's an Acid just not as dangerous as Sulphiracs. Fumes will make you gag, or light your nose hairs on fire. Use ventilation.The 30% I placed a few rustry bad powdery bad bolts just to test. Wow reacted right now. So it was chewing the rust off the bolts. Left overnight. Got them out. Brushed with soap and warm water. Then rinsed in a baking soda water rinse to absolutely neutralize any acid hiding anywhere. Worked for me. Good luck.