One that I had a realy strong positive first impression with, however, is something that may not be an option. Could find very little information; and it was all old. Looks like this was an Evo cover. Apparently produced by Milwaukee Iron but that information was sketchy. Found one site that listed it as still actually being for sale and carrying a description of "1993 and newer big twin" or something like that. But it simply might not have been changed in so long that the ad originated back when Evo were the contemporary animal.
My first thought was to mount it tail down. So you'd have a small oval between the cylinders showing more of the motor while (hopefully) having just enough oval to cover the breather hardware behind it. The rest of the tail would then match the contour down between the cylinders.
Information on this thing, however, is hard to find. Even if it's not available in a center mount I'd not be averse to addinga hole and a countersink to make it center mount if there's enough material there to work with. Email currently hanging to a couple of places that had any information at all currently online to see if they can offer up more.
At least it's an idea....