may also sound naff, but a few stick on chrome effect badges, or detailing such as fake studs on the side would add to the period effect,if not overdone - although it may detract from the original version. Should image you can get things somewhere. It may also only look good as icing on the cake , if other chrome work is done.
I think if I was keeping it as it is,( which is what i'd prolly do) I would just add a chrome effect add on window rubber finish and a couple of studs or something. A very thin outer rim of chrome finish ( if you can get it )around the lights may also add to the effect and be easy to do if it bends. Then you have a splattering of chrome all over, - the outer rims, the head cages, the wing mirrors, the windows, the mirrors. This in effect can be seen on the original - little bits of chrome detailing ,badge, studs, front light fixings, etc etc