Vintage Speedsters and other makers refer to their molds as a 1957 model year, or 356A. Therein lies the rub, since the model change was mid-year, in March 1957. Prior to March, the tail lights were beehives, with a shine-down light. From March 1957 on, teardrops with shine up lights took over. Thus, both configurations are correct for the model year. Porsche lore is also filled with anecdotal information regarding exceptions to the rules, special orders for export or the US market, etc.
Most of the nitpicky details are only important to "points" cars, i.e, show cars and their cadre of OCD owners/afficianados known as the Porsche police. I'm glad those folks are around, since they do such great restoration jobs. However, the oondescension they exude toward replicas is only bearable for a very short duration.
OTOH, my replica has no Porsche badging. It's not a Porsche, any more than a funny car at the drag strip is a '66 Nova. I'm glad it's not an original Porsche as I love the shape, but want more power, better handling and balance, more efficient brakes, and the mod con's of today's cars.
My advice is to enjoy what you buy or build, and make it your own. There's nothing wrong with asking for advice, but it's your creation.