Yellow plastic vac line in the engine compartment is the lock supply line.

You should be able to unlock the trunk with the key. However, they can be somewhat tricky (at least on my W108) -- you may have to turn the key slowly toward the unlocked position while repeatedly pushing it and the button in and out until the latch "catches" and open. Big PITA.

I'd try the vac lock system with a Mitivac before I'd drill a hole!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!