I think the following header:
SET client_encoding = 'WIN1252';
should be added on top of Chinook_PostgreSql.sql since it actually use that encoding, but the default for psql is UTF8 nowadays, no matter the encoding of the target DB.
So, if you type
psql -f Chinook_PostgreSql.sql TestDb
you'll end up receiving a lot of errors:
psql:Chinook_PostgreSql.sql:237: ERROR: invalid byte sequence for encoding "UTF8": 0xf4 0x6e 0x69 0x6f