I think this will fit all other models. This came from my '09 GTV 250. Its easy to install. I think Scooterwest has a video or try Youtube.

Side stands are surprisingly controversial. Vespa installs these on many models around the globe but the USA requires an interlock switch so the bike can't run with the side stand down. So all US Vespa come without the side stand tho I think they've been including them with the interlock the last couple years. You can purchase side stands after market from various sources such as on scooterwest.com. That's where this one is from.

Here's my take on side stands. I have been using one for the better part 10 years. My bike has never fallen. Many people think they will cause your bike to fall because the side stand will retract when the weight is take off the stand. However if you park the bike slightly uphill or on a flat surface the bike rolls back just to bit and the stand stays retracted. No problem. You do not want to park the bike with rear wheel higher than the front wheel. I almost always use the stand for quick parking but never for more than a few minutes and never in public where someone could nudge it and cause it to fall.

I recommend replacing the springs. These are getting old and losing their spring and are a bit rusty. Make sure to use two springs. One is a back up of the other. You DO NOT want the side stand to come down while you are making a left turn!!