'74 LP Custom Serial # 550077

Just curious if anyone else has a similar unit to this one... it's a cherry sunburst which I've brought back to life with a true bone nut replacement and bridge replacement and complete setup, plays like butter, got some abuse in the past and is maybe a 'rescue guitar' but the paint is actually really good on both sides, 3-piece neck, and sings like an angel now with perfect intonation. The serial number is interesting (550077) and I wondered if this truly is a '74. Thanks!

Most probably a very late 74 or 75 with 55xxxx serial. Mahogany or maple neck? Some photos would be really helpful.