Thanks again for all your help GeneralDisorder.
Here is a Bosh Relay that I think will work. It seems to be a 30A dual circuit NO relay with both circuits closed when it is activated. Only one side would be needed for this application.
Bosch 332019150 Relay
It appears to be marked with the Pin numbers you described in your post:
"Yes it's very simple. Battery positive (through fuse) to normally open relay contact (pin 87), relay contact common terminal (pin 30) to starter solenoid, tie the old solenoid wire to relay coil positive (pin 85), and relay contact ground (pin 86) to chassis ground."
If you could confirm that said relay will work, I can draw a quick electrical schematic and post it so as to assist others that might be wanting to do the same thing.
The link below is where said relay could be found on Amazon to anyone so inclined.
https://www.amazon.com/Bosch-332019150-Relay/dp/B0010ADJIE/ref=pd_day0_263_1?_encoding=UTF8&psc=1&refRID=89J2X94MX54ZC7J4EK12#Ask