Yamaha DTXpress/DTXplorer/DTXtreme

John,

I didn't spot it was you otherwise I wouldn't have sent USA links! Thomann used to be the best place for parts but I cannot see the stopper on there.

I have the service manuals for some of the Yamaha components and it lists "spare parts".  I think the wing nuts, felt and washers are the same fitting as standard acoustic hardware so a normal drum shop should be able to help with that.

In the UK, http://stores.ebay.co.uk/LondonTradingPost is worth a look.  Even if he doesn't list the part you need, it may be worth asking him.

Keith