55.2-59 1959 recirculating heater core - any retrofit options?

[nikwho]

Hello all,
Well, now that I'm wrapping up my transmission swap and have scratched about everything else off of my list to get my '59 to daily driver status, it's cold out! I've got a recirculating non-deluxe heater in my '59 Apache. I honestly haven't tried pressurizing my heater core as of yet, but expecting the worse, as this truck sat for at least the past 25-30 years with the heater core not plumbed. Assuming it leaks. I will probably pull it, see what needs attention with the blower motor and switch, then drop my heater core off at the local radiator shop, to see if they can test and/or repair it, as needed. But, before I go in there, I wanted to see if anyone had found a good retro fit heater core for this application? There are so many different heater cores out there, I figured that something, from some other car would probably fit right into place of this heater core, with the fittings routed in the correct place. If there is a super easy swap, where I'd be able to keep my otherwise original heater, I'd like to know about it and know that cost, when considering whatever price I'm given by the local radiator shop. Any help would be greatly appreciated!

Nik