Marcus
Which model of Lurem do you have? If it's one of the commoner ones like the C210B, or the later version that was badged as the Maxi 26 by Record, someone might be able to take a photo/provide dimensions of any missing part.
And if it's the Grandaddy of these, the C200, mine is measureable/photographable and has a very tatty photocopy (or it might even be a stencilled version - remember those??) of the (French) manual.