I don't think I would go with SEI anyway. Their paint is really fragile. Not so big a deal with a removable component, but a transom is anything but easy to remove and repaint.
Thanks for the replies. I am in North Carolina.
At the very least the transom plate needs to be replaced. I had to cut one of the engine mount bolts off because one of the ears that captures the nut was broken. The bell housing and gimbal ring have quite a bit of corrosion from being in salt water and the tiller arm is very rusty.
I am thinking new because I want to do this one time. Quicksilver is $2700, SEI is $1700, and I've seen clean used ones for $1100. Of course any used one will likely require that all the bellows be replaced.
I bought a complete OMC Cobra transom assembly including the trim rams for $450 from eBay. It’s in very good shape no corrosion or damage, so keep looking if anything there are way more Alphas out there than Cobras!