Trunk stuck closed - 1976 300D

[j-galap]

Hi folks,

I've been doing some work on a '76 300D recently and the owner has been in touch to say that the trunk no longer opens.

Apparently it makes the clicking noise that sounds like it's going to open but it just doesn't.

I was thinking about trying the technique of pushing out the round trunk floor insert, reaching through and unwinding one of the rear lights and then reaching through the light lens hole to then unbolt the lock mechanism by feel. I can also use my own car (1974 240D) as a blueprint - assuming it's the same - to help with this.

Anyway, before I start pretending I'm a professional safe cracking ninja, I thought I'd post here to see if anyone has any other methods to try. Any ideas?

Thanks!