Create a new, work db. Create 275 procs from the existing code. Hopefully that's as as adding "CREATE PROCEDURE proc_NNN AS " to the beginning of the code and running it. Then use view sys.dm_sql_referencing_entities to find all objects (it doesn't seem to always list all columns, but hopefully in this case it will list them all).
SQL DBA,SQL Server MVP(07, 08, 09) A socialist is someone who will give you the shirt off *someone else's* back.