The photo Gandhi's former paramour shows to Elaine depicts 'the Mahatma' without a mustache. The real Gandhi (1869-1948) always wore a mustache in his later years.
Kramer and Newman both refer to the record store as "Ron's Records" as does Ron himself. The sign outside the store however, clearly shows the name is Bleecker Bob's Records.
When Jerry visits Mr. Fields in his apartment, he calls him "Mr. Bill" which is the actor Bill Erwin's first name, not the character's (Sydney Fields).