ah, now I can see too. Thanks!
Indeed like MRC Batwings
but with carrier for the cable and brake shoe mounting like from Crystal Design
According BikePro, there was a pretty close cooperation between McMahon and Russ Crystal.
They had some joint pieces like cable hanger.
"MRC is involved in the marketing of a commonly designed and manufactured carrier with Russ Crystal of Crystal Designs called the G-Spot. The G-spot is sold separately".
Maybe at your brakes a arm design from McMahon was used but manufactured from Russ Crystal, using the typical 3rd party brake shoe holder he has used for his own designs and also his cable carrier?
BTW: can you please share a bit of more details to the left ones on your picture below?
The right ones are the Batwings.
Does this belong to a McMahon Power-Link U-Brake (like shown here at the left)?