I've got a Silverball Mania I had picked up as a pile of parts that someone had started tearing apart to do a playfield swap but never put it back together.
I ended up putting the original playfield back together as it wasn't in bad shape other than wear in the horseshoe and damage from the 2 center posts in front of the horseshoe.
Its not a terrible machine but may get boring if its the only one you own. Although it is rewarding to rebuild this thing and getting it working and playable again.
I'm just wondering weather its worthwhile to do a 7 digit conversion on silverball though.