ms 1000 i believe stands to reason 33 1/2"
sofa 25"
if i understand you correctly
MS275 sink is 8.5" LONG (lets call it long now for sake of argument- anyways),(width is 12"), but the 2125 is 17" long (and width of 12")
and it looks as though the centers are 1/4" off each end- NO?!? might be wrong... but inclined to think you line/stack up a row of 275's, 430's, 2125', and look down all those mounting holes like a barrel of a gun... straight down/through)
(2125) 17" + (275) 8.5" = 25.5" - .5 = 25" coc (center on center),
MS1000 would be 17 x 2 = 34 - .5 = 33.5 coc
Right? i think so anyways
ARE YOU SURE that the FAS is 27.5"???
isnt the 430 = 12" and the 2125 = 17" so that would be 29 - (.25 x 2) .5
just off the cuff- my thoughts-
Later i will actually go measure unless someone beats me to it.
I have the following 275, 430, 2125/2250, 1000 and bid grandpa surfboard sinks all naked and stripped for easy measuring (and photo taking

)
Thanks for bringing the question up though- I prolly would have let the chance pass by before taking picture of all together like that- prolly will not happen ever again like that with these sinks whence they land in their owners hometown/land... before loosing the chance i should get on that...!
Isnt that what you call (all the planets- i mean sinks- lined up)
Maybe i should take pic of all the sinks lined up along side of the entire family- up to the big daddy surfboard...
watch guys this should be neat!
m