This is a sensational surprise to me, but... a few small details need to be clarified.
If the Z1701 was bought in the US Spring 1984 then it must have been built at least 2 months earlier - this means a production date of March 1984 at best.
The frames built for Team Panasonic for the 1986 season are known to be Z45xx - they could have been built as early as September 1985.
This means that in a period of 1,5 years about 2800 frames were built, so the average capacity in this period is less than 1900 frames per year.
In his statements in 1989 Merckx emphasized that from 1982 onwards the number of frames built increased steadily (year on year).
By the time the Z1710 was built, about 13500 frames had left the EMC factory - if it had been built in spring 1984, the average throughput over the 4 years of production (from spring 1980 to spring 1984) would have been about 3400 units per year.
A drop from 3400 to 1900 would have been an easily seen disaster.
If the Z1701 had been built in the spring, the pro teams would have used the Pro SLX or Pro 753 (and they were already in production, their designations are often earlier than the Z1701) as early as the 1984 season - yet they were not used until the middle of the 1985 season (a year later)
The only thing that would help is a proof of purchase with date and serial number.
Starting in September 1984 on this bike (if it was bought "the day before" it would have been built in July 1984 at the latest anyway) changes our numbers to 3000 and 2400 - still doesn't look good and doesn't solve the Team Pro SLX/753 problem.
My dating (would be December 1984) gives numbers 2800 and 3600 and fits the Pro SLX/753 problem - but is not supported by any document....
Dating 1980-1984 is a nightmare