I don't think you'll need fenders. This is the custom vehicle section of the inspection manual:
DEFINITIONS
1. “Custom Vehicle" means: a. a motor vehicle that is at least 25 years old and of a model year after 1948; or
b. was manufactured to resemble a vehicle that is at least 25 years old and of a model year after 1948; and has been altered from the manufacturer's original design; or has a body constructed of non-original materials.
c. A custom vehicle is primarily a collector's item that is used for: club activities; exhibitions; tours; parades; occasional transportation; and other similar uses.
A custom vehicle does not include a motor vehicle that is used for general, daily transportation or is a vintage vehicle (UCA 41-6a-1507).
2. "Vintage Vehicle" means a motor vehicle that is 30 years old or older, used primarily as a collector's item, and used for participation in club activities, exhibitions, tours, parades, occasional transportation, and similar uses, but that is not used for general daily transportation.
A. A vehicle with a vintage license plate does not require a safety inspection. A vehicle may be registered as a vintage vehicle if it is 30 years or older, used primarily as a collector’s item and used for participation in club activities, exhibitions, tours, parades, occasional transportation, and similar uses, but is not used for general daily transportation.
B. The following are minimum safety equipment requirements for a custom vehicle:
1. Hydraulic service brakes on all wheels with current vehicle brake and stopping standards.
2. Parking brake operating on at least two wheels on the same axle.
3. Seat belts for all passengers and driver.
4. Sealed beam or halogen headlamps.
5. Brake Lamps.
6. Turn signal lamps and switch.
7. AS-1 safety glass or Lexan.
8. Electric or vacuum windshield wiper in front of the drivers view.
a. Reject when:
i. Any of the above requirements are not met.
C. Exhaust systems may discharge along the side of the vehicle provided they discharge at a point behind the rear edge of the door and exhaust is directed away from the vehicle.
DEFINITIONS
1. “Custom Vehicle" means:
a. a motor vehicle that is at least 25 years old and of a model year after 1948; or
b. was manufactured to resemble a vehicle that is at least 25 years old and of a model year after 1948; and has been altered from the manufacturer's original design; or has a body constructed of non-original materials.
c. A custom vehicle is primarily a collector's item that is used for: club activities; exhibitions; tours; parades; occasional transportation; and other similar uses. A custom vehicle does not include a motor vehicle that is used for general, daily transportation or is a vintage vehicle (UCA 41-6a-1507).
2. "Vintage Vehicle" means a motor vehicle that is 30 years old or older, used primarily as a collector's item, and used for participation in club activities, exhibitions, tours, parades, occasional transportation, and similar uses, but that is not used for general daily transportation. 50
D. The vehicle identification for a custom vehicle shall be a number stamped on the frame of the vehicle. If no such numbers exist, then the requirements as established pursuant to Administrative Rule R873-22M-15 (Department of Motor Vehicles) must be followed in order to pass inspection.
E. All safety equipment of a replica vehicle shall at least meet the safety standards applicable to the model year of the vehicle being replicated. Any replacement equipment shall comply with the design standards of the replacement equipment’s manufacture (41-6a-1507).
However, it does say they are optional on 1935 and older vehicles, so maybe they are required? Lots of ambiguity on the DMV website regarding custom/kit cars. Either way, I love it!