M113 Beobachtungspanzer Drawing

Does anyone have line drawing/dimension information showing the additional superstructure on an M113 Beobachtungspanzer. Looking at stratchbuilding one in 15mm and it appears to some simple geometric shapes but I need/would appreciate the dimensions

Does this help?

http://www.panzerbaer.de/colours/a_relaunch/bw_beobpz_art-a.htm

Thanks, yes I have now found that one. And appears to be 1/50th so a straight measure and divide by two

Take a look here: http://www.panzer-modell.de/referenz/in_detail/m113_optronic/optronic.htm

Greetings
Wolflord