1937 Cord Heater

Thanks to Pete/Laura I do have an original heater in my car. I always thought I did but with mine having 4 mounting bolts and the firewall diagram I got from Stan in 1975 his shows only 3 bolts holding the heater to the firewall and the hose holes are in different places. My question is about the motor wires. I don't see a color difference and need to replace the wires because of the age of them. What wire do I need for this small job and where can I buy it. Or am I just stressing over nothing. I realize most any modern wire will work fine but I really want to make it appear peroid correct. Thanks for any help offered too.