Heater Hose

The heater hose that came our of my KB-3 is Gates Safety stripe 5/8". If is black with a red stripe but I suspect not original. Was there any special look about the original heater hose? Was it black or red?

I doubt there might have been an identifiable OEM heater hose. IHC most likely bought heater hose from GATES, GOODYEAR or one of the other hose makers. Lowest bid price likely supplied the hose.
It is very unlikely the hoses on your 70 year old truck are original. The hoses may have been changed a few times. NAPA will have a good quality heater hose in bulk. If you want to spend a little more money, the Silicone hose have better flexibility and the silicone are predicted to last many times longer than rubber.
If you buy and use modern hose clamps, do not overtighten them. The correct tightness is when the rubber surface of the hose is just starting to come through the track in the clamp. If you decide on silicone hose is a very good idea and almost mandatory to use hose clamps that have a slipper. This keeps the softer silicone hose from being cut
I only use GATES rubber now. They are cost effective and common.
I like to try and keep the GATES strip in-line. This, to me, means no twists. I prefer the black stripe hose over the silicone red hose for looks.
I bought AEROQUIP stainless braid hose and fitting for the HVAC on my 1940 Ford. This may be the most expensive and the last time I buy this hose. The hose and fittings were $1365 cdn, nearly double the cost of the total Vintage Air system. One fill and test 90 degree fitting was $265. The Aeroquip braided hose was around $300. The balance was fittings. BTW, I needed to buy a special tool for installing the fittings. Take this a warning.