where are u getting your rebuild kit from ? the ripoff on fleebay ? Tyga are $113au plus postage that is cheap as chips . I scratched a barral on my mc21 and i got a pair of barrals of japanauctions for $200 in top condition so now i have a spare and way less than a replate . If you go that way make shore there is a pic of the bore . Here is one http://www.japanauctioncenter.com/view2.php?seturl=http://page9.auctions.yahoo.co.jp/jp/auction/k125494024
or here
http://www.japanauctioncenter.com/view2.php?seturl=http://page5.auctions.yahoo.co.jp/jp/auction/e101224894
and here
http://www.japanauctioncenter.com/view2.php?seturl=http://page4.auctions.yahoo.co.jp/jp/auction/d108665139