I had hoped one of our Birdview owners would have chimed in by now...
Without pictures, I think all you need to do now, is take a regular C-band scalar and sandwich it to the face of your now-flat Birdview scalar.
There are two possible approaches:
- machine off the back side of the new scalar so it's flat
- bore out Birdview to take the back side of a scalar (only about 3", not 6")
The BSC-621 hasn't gotten a good reputation on this forum by a lot of people.
At least not for Ku-band operation.
How well it would mate up to a Birdview is an unknown.
Our most experienced Birdview owner, Linuxman, has posted a number of threads in the BUD section of the forum over the last couple of years.
I'd suggest reviewing his work.
From reading all his comments, my impression is that the
CK-1 dual-band LNBF worked well .
He's got exceptional patience and skill, so how he'd have done with a BSC-621 is an unknown.
Some of the Chaparral corotor and orthomode models worked slightly better.
You'll have to read his threads for more details.