Congrats! I am compelled to make one last pitch for Lubro Moly Tacky Lube Spray. It is amazing stuff. I asked my indymechie about Lubro Moly products in general and he said "dunno, ever use this?" (Whipping out a can of the stuff.) He praised it highly, has used it over 15 years. Fixes crappy and worn latches nothing else can. Best price I have found is etyparts.com.
And fianally, yes, lube lube lube, twice per year.
1986 300E Anthracite + ECodes + MB Mileage Award