Silver series crossover changes?

As you already know that I'm searching for the elusive WP-1220 surrounds I have come to the ultimate conclusion that 1 they are not available 2 you that might have them are hoping to hatch them to higher expectation 3 Since I don't include any s a rhetoric to the site no one wants to help! Are any of these assumptions correct? Enlighten me to further possibilities!!

Now on to the topic at hand. In changing to a non extinct 12" woofer 8 Ohm rating what specifically would have to be changed? I have near novice circuit skills but can figure stuff out with a little help. Thats what I"m asking for.... Help~

The only replacements for the Silvers woofers I'm aware of is thru Orovox.

Thanks Rabbit!!