3rd gen muffler flexible joint seal! Where to find?

I just realised I have a huge problem!

As the home made exhaust of my 3rd gen (that came on the bike) had corroded so it did brake, a friend welded it for me as a temporary repair and it needed some sealant to hold tight so I could ride the bike until I got a replacement muffler, a nice stock one (thanks JohnLondon!), in fact I let it be as a winter/next year repair. But the sealant did glue to the seal well, to well, so as I did take off the repaired muffler, the seal on the collectorbox came along, and it was impossible to take it off undamaged. Now that I wanted a new seal, Honda part number: 18532-MT4-000,  I just found out its now longer available! Help!.... Ok I know many cars use seals alike, but local store had no match in stock, and can´t order one whit measurement, they just can order if I know what car model and year use one that fits...bummer

So, can someone here help me?

Try here:

http://www.hondateileguenstig.de/shop/advanced_search_result.php?keywords=18532MT4000&x=10&y=15

Thanks Dutchy! Hope it works, just did order it!

Another alternative is to pack the inside of the domed connection on the end can with exhaust tape.  Those exhaust gaskets are becoming rare of rocking horse shit

Looks like I did score, got a e-mail that the order status is delivered, but I assume that is its posted. Have to see if I get a package from Germany later this week.