MoFi or Harbeth (used)

I have no experience with the MoFi speakers, but based simply on their price point and what I've seen/heard from other MoFi electronics (the UltraDeck and MasterPhono), I think their speakers would be hard pressed to outdo the Harbeths, but that's purely conjecture.  I've been impressed by the MOFI gear I've heard to date, but it seems to be priced above it's performance level.

I picked up a pair of 30th Anniversary Compact 7's a few months ago, just to compare to the other Harbeths I've owned (Super HL5 Plus 40th anniversary and P3ESR SE).  They really wowed me, as well as some of my audiophile friends, and I kept them for months, seriously considering keeping them over my KEF Reference 1 speakers.  At the end of the day, the KEFs are better, but I liked the Compact 7s over the Super HL5 Plus as well as a pair of Stirling LS 3/6 that I had.  They are great speakers.

Toeing them in could help or perhaps your preamp has balance controls.  

Have a look at KEF Reference 1’s. 

I tried to stay away from suggesting things other than what the OP said they are considering, but here goes...

This not a bad recommendation, but the KEFs might be too much speaker in a room that size.  I have the Reference 1s as well as 30th Anniversary Compact 7s and did an extended (about 2 months) comparison between the two.  The KEFs won in my room, but not by much.  The KEFs do soundstaging better (again, not by much) than the Harbeths, which is a plus if you're going to be off-axis.  Overall the KEFs are more dynamic, and are just slightly better in the areas of clarity, imaging, and as mentioned soundstage.  Both are tonally pleasing, with the Harbeths having a slight edge there.

If we're going to toss other speakers into the mix, I recommend trying out the PS Audio Aspen FR5 speakers.  They are a bargain at their price point and have very wide dispersion, which would be a plus with your off-axis situation. PS Audio has a very generous return policy, so you can do an in-home demo and return them if they aren't too your liking.

A friend who has KEF Reference 1 Metas recently did a shootout with the Ref 1s and the FR5s and ended up keeping the FR5s.  While the KEFs are "better" in almost every way, they overloaded his small room while the FR5s created a much larger soundstage in his small space.