Welcome to MLO forum. Congratulations on your recent great ML acquisition.
Motion 40 are fun to listen to. I heard them some years ago with Quad stereo transistor power amplifier and they had a great engaging sound. You must have got a good price on them since they are no longer manufactured.
With the not one but two subs the low end may be further reinforced giving overall great sound quality.
What amplification do you use?
Sonics may improve substantially after break in period is over. Enjoy!