SUCCESS! I recently started restoring my 74' Jensen Healey and realized the trunk was locked...and the past owner didn't have a key. Jim at Delta Motors suggested I remove the glove box...and take it to a locksmith, since the same key opens the glovebox as the trunk. I did exactly as he suggested...and for $8 I had a key made! It works great! Thanks Jim!
There's a spare key, or should be, hidden in the engine bay of the JH. With the hood up it's located on the back side of the radiator support panel, on the left side facing the car and is screwed to the triangular panel/fillet near the radiator overflow bottle. Colin