I always encourage people to mod their Bug according to their taste!!
BUT, this time I have to sya, in my personal opinion, the "Super Beetle" (with the curved windscreen and dashboard) will not look right with early fenders etc. As a matter of fact, I am not sure that the fenders will actually fit, but I stand corrected on this(I am NOT going outside in the rain to take fenders off a 60's look Beetle(and the 1303) to do the swap to confirm!!!

)
But then again, it IS your Bug and go for it if you like!!