I have threads and threads regarding these. For the money, I could not resist. I bought one off the bay from Caltric. It is a chinese middleman from LA area. When I told them the solenoid was likely bad, they said to simply return it on a 1 year warranty. I asked if we could avoid all the heavy shipping costs round trip and if he would just send me a replacement solenoid. He did.
I though it was giving me problems a few months later and ordered a Wilson. It came; but I think they sent the 12Volt unit by mistake. I put the chinese unit back in while I waited for a 24volt Wilson. The Chinese unit is still cranking; but at least I have the Wilson on the shelf in case the Caltric goes. I pack the spare when I venture afar.
I'd get a Caltric off ebay; but I would have a shop rebuild your old core. Shelve it along with the correct bracket.