Modern Vespa

Firstly let me say just how impressed I am with this forum.
OK now I'm working on my mp3 I realise there are more than a few screws holding that lovely plastic missing or swapped for normal steel screws. Is there a common size or sizes so I can order a batch. Also with age doesn't the age gremlin just snaffle screws just laid down. Hope I'm not annoying just tip toeing my way thru jobs

Look on Fowlers of Bristols web site for your model as alot of the self tapper type screws are listed by size however unless you buy them from them all the sizes that seem to be commonly available here in the UK do not seem to match piaggio's i'm not sure if uk ones are made to old gauge size and piaggio's are to a metric size which ever way it's a right pain in the b-m i've tended to get black stainless self tappers via ebay and next size up from piaggios.