This is a nice and simple recipe. Because it makes slightly more than a gallon, it is a excellent mead for a novice. When you go to your LHBS (local homebrew store) to buy the yeast, buy a hops sock for the grated ginger and put some clean marbles in the hops sock to weight it down and a string to pull it out. Fetching out grated anything is a royal pain.
Also keep refrigerated and covered.
I prefer Lalvin EC-1118, the author prefers K1V-1116. Try both and see what you prefer.
This is an excellent recipe for someone who has never make mead before because it makes no presumptions about prior knowledge and it is makes a quantity that is manageanble for even a novice.
I suggest that the author uses proactive to mean stainless steel. This recipe is from a 1962 publication and quality yeasts were not abundant then. I suggest using either Lalvin EC-1118 or Lalvin K1V-1116 AND I suggest adding 1 teaspoon of yeast nutrient after you pitch the yeast. 55 degrees Fahrenheit might be on the low side, but keeping in the refrigerator will do the trick. Also keep it covered in the refrigerator so it dose not pick up other food tastes. Do not bottle until it's six months old and do not worry about how long it takes to consume.
Do not boil the honey if it's already been pasteurized. Put the shaved ginger in a weighted hop sock so you not have to fish it out. Also consider not adding the corn sugar for priming. I have never heard of sparing a mead must.
A final gravity of 1.020 seems high to me. I would suggest a gravity below 1.010. I would also suggest aging for six months before bottling.