I found my mother's copy of this recipe and have updated it for the amount of !cheap! caviar to buy. She says to buy 3 "large" jars of caviar - it seems that small jars have 2 ounces and large, 3.5. I've attached pictures of my mother's handwritten instructions.
Grease a 10-inch spring-form pan with a little mayonnaise.
Mash eggs, mayonnaise (just enough to hold eggs together), salt, and pepper together. Spread into bottom of pan.
Spread scallions on top of egg salad.
Mix cream cheese and sour cream until smooth. Spread over scallions.
Recipe can be prepared up to this point the day before (recommended). Place the spring-form on a paper towel on a plate (the sour cream tends to separate).
Spread the caviar into an aesthetic design use wax paper for masking and toothpicks to move caviar. We frequently made a diamond in the middle using 2 jars and then did the exterior area with the remaining jar. Alternatively, you could do a half-and-half pattern with four jars.
Serve with plain crackers such as Carr's Table Water Biscuits.