Looking at my BL82 again you have everything just right for cop car coverage (excluding space bar) as far as I can tell
I'd be very interested in a 6u space bar kit so I don't have to try and get a closest possible match from another vendor or wait to buy a separate space bar later
if Signature Plastics do have a mold. Could you possibly ask SP when you place the order if this is possible? BL82s might not be so common, but I'm pretty sure there's a lot of 1800s out there.
I'd also be very interested in a lambda kit (even if it has to be run separately after the main groupbuy) - Have you been in contact with Valve yet?