The design of the Coupe nose gear ( wheel canted forward) is inherently subject to shimmy. Most aircraft with gear like this have a shimmy damper. Experimenting with different tire pressures may help. Also if the wheel is out of balance it could cause a shimmy. With this poor design keep all the scissors joints snug, also the steering knuckle should have no slack. Some of the cars from the 30's & 40's used to have front wheel shimmy until the designers learned about cambering (canting) the spindles correctly.
