The Deckas 52T chainring fits.
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The point of interference is about 5 mm forward of the chain, where the down tube expands as it rises.
I had a couple surprises during the installation:
1) The Specialized ring would slip over my oversize pedals, but the Deckas would not. So, break out the pedal spanner.
2) The new chainring bolts are conventional in design and there was insufficient clearance between the plastic motor housing and the back of the chainring to fit my wrench into the slotted nut. So I had to remove the plastic housing around the motor. That worked so that I could torque the steel bolts to their recommended 12 Nm.
I chose the bolts here:
RocRide Bolts
I prefer the strength of steel fasteners and coated them with a waterproof grease to cut down on galvanic corrosion with the aluminum rings.
My test today showed that I could more easily keep cadence down a steep hill to my house, a hill where I want to go 40 mph in order to blend into traffic. This was the whole reason I did this little conversion, so... Success!