If Graham can't help you out with a radiator, I've got a few 24v Senator one's sitting in my garage you can have one for the cost of posting.
I hope it's not your CHG that's blown, having said that, it's not really that hard to do.
Keep an eye on the coolant. Check for oily deposits in the header tank and mayo in the oil, As has been said before, get a sniffer on the header tank to see if there's exhaust gasses there, (although when the CHG went on my Senny, the sniffer didn't detect anything even though I could only get eh header tank off with a pair of pipe pliers.).
IF your CHG has blown and the oil and water is mixing, (particularly if there's water in the oil!!), then your engine will be toast in about 2000 miles. The bottom end doesn't like exposure to water and destroys the big end(s).
BUT, I have two engines at my disposal, one with new guides on it, but is unrun and one from a Carlton GSI, which was sound the last time I drove the car. We can 'arrange' something if need be!
On the subject of fans, your viscous set up probably stopped working years ago! However, if your car has/had air conditioning, then there should be an electric fan already on board. This is controled by a 'waxstat' which is screwed into the radiator about 2/3rds of the way down the tank on the near/passenger side. You could do one of two things. Purchase a lower temperature waxstat from Vx and and use that to trigger the fan at a cooler temperature, (I think you can get them to start at about 90 degrees,), or bridge the wires and run it permanently or rig it up through a switch to use manually when required.
Good luck!!