Anvil project; I could use some positive advise on my last anvil project. 30 + years ago I made a pattern and had my anvil cast of Ductile Iron. I work hardened the surface and used it as my portable anvil (178 lbs). Somewhere in the 80’s I contacted a machinist school and the agreed apron plan was to make a hard steel top, dove tail both and press fit them. When I showed up the top was bolted on, now told to have it flame hardened. When I picked it up they told me the plugs covering the bolts popped out and they replaced them. The anvil was dead after that but I used it anyway till now. I removed the plugs (grease in a hole trick) found one plug was a mistake they tried to cover up, I blued the two halves and ran a file across both and I have no clue what’s going on, I have a hollow spot between the two halves. I was thinking to have someone re surface both and I’ll bolt them together in hopes to have a good city anvil like originally wanted.