The last article in a well known cooking mag. said that fresh eggs last a long, long time if refridgerated! Like maybe months,it said up to a year!! The effects would vary with regard to freshness. I personally have kept them for 6 months without problems. May depend on the temp too. So it probably stands to reason that boiled eggs would last that long ,or longer.
Baluts, haven't heard of them since my brief stay in the Phillipines, long, long ago! And they suck by the way! If you can get them past your nose!