A Purist's Read
My dad and I always try to keep our scooters as original as possible and do not like changing parts old for new but, of course this is necessary sometimes. Our Vespa SS 180 which is our most original scooter, currently still has its original carb but can only imagine if something goes wrong with it, we will have to spend roughly £600 looking for a replacement original, or will have to look for a conversion kit with a modern carb, which we really don't want to do. I would have thought that companies such as Dell'orto would have looked in to creating a replacement original which was a less expensive alternative if the carb was on its way out. The trouble changing from an old carb to a new carb, is the fact that you lose the authenticity. As other purists can relate, you would prefer to keep the old original parts as long as possible. I have had to change the throttle slide on the original carb on the SS as that was worn ,and have now had to change the float as it was old and not doing its job anymore. Its only going to be soon where the carb needs to be completely changed. But I suppose they are vintage and when you have something that is old they become money pits.
The photo below is my dad and I's Vespa SS with the original carb and air filter. Something like this you do not want to change and in my opinion is something that I would like to try and always keep original.

Vespa SS carb together

Vespa SS carb without the air filter