Gene Berg offers a cool looking oil fill/breather, that's called Porsche-style. The original 356 "cans" are always on Ebay, usually with the gen stand as well, that's where I picked up mine. You then remove the mounting flange from the Porsche stand and weld it (or bolt it on with counter sunk allen heads and a dab of JB Weld beneath to prevent leaks) onto the VW stand where the stamped steel filler went.
It sits about 0.5" higher but still fits no problem and looks like it belongs, 'cause it SORTA does in a "prodigal son" kinda way.
I went with the original Porsche oil can filler and remote orange Fram filter/canister set-up in order to keep the 356 prototype engine illusion alive. Another cool look is to strip the paint from the aluminum Bosch Blue coil, polish it, remove the "Bosch" casting from the bakelite top and re-sticker it as a Magnetti Marelli unit, I guess that these were the "hot" coils of the day and came on the Abarth cars. I made one and it looks pretty neat, I also re-covered and stickered a voltage regulator as well.
It's a TON of fun once you get started with the illusion . . .
Luck,
TC