Internal tenement flat door intercom

Can anyone advise please? We would like to replace our 80's/90's tenement door intercom with a vintage bakelite one we have. Although both units have internal buzzers and entry buttons, wiring is not exactly like-for-like as bakelite version has one less connecting wire and different circuitry. Does this sound possible? And is it a an electrician or telecoms job? We have photos of both internals if needed.