Not sure what brand kit I purchased (eBay) They rubber parts are good and fit well but the rings leave a lot to be desired. All but 1 original flat ring was reusable front and rear ( I like originals much better anyways) In order to use the 1 ring from the kit I had to trim it down quite a bit ( ends overlapped) and add a little tension and I. Still not crazy about the fit.
I am not familiar with the size dash 013 or - 013. I found them if they are "O-Ring-Dash-013-EPDM-0-07". For only a couple bucks I ordered them.
If you see a request for a couple rear pistons from me, you'll know how assembly went. Lol. In for a penny, in for a pound