Gray water drainage design help (see drawing)

The bayonet fittings are not necessarily interchangeable! I just found a leak in the grey water valve and found the pipe flange to have an ear broken off. When I took the other 3 bolts out Icould see it had allways been in a slight bind. Went to the local TT sales and they fixed mr up with the needed repair parts. Every thing looked the same but then I found the new valve flange has a slightly different bolt pattern. They also have a different diameter boss where the seal to the valve sits. Valterra is the brand of the replacement parts and the origonals aredifferent. I can't remember the brand except it starts with a "B" and it is outside under the MH and I am inside where it is warm . So, make sure you check for compatability between brands. I should get mine straightened out today. Jim.