If you have a case saver, you should be fine. They are still available from HONDA the last time I checked. It's a metal piece that runs between the sprosket and the case so that there's no space for the chain to 'wrap' around the sprocket and it slows the momentum from wacky your case. It mounts with the same bolts behind the sprocket cover.
As far as the black mud flap, they are DISC. from Honda and are very hard to find in one piece. Many have been broken over the years from falling off the fenders or from wheeling over onto them. Depending upon the shape, I've seen them go from ~$65 to ~$150/200 on eBay.
Bruce
'85 ATC350X - "Showgirl" '86 OEM plastics/Fork boots, Rear Axle/Rotor/Hubs, Hondaline Fender stabalizer/extender, Speedo/Tach, Tank cover.
'86 ATC350X - 'Go-Go Girl'
'82 ATC250R - 'California Girl' - Progressive springs F and R, Hondaline HL Guard, Fairing and Speedometer.
'82 ATC250R -'Snow Bunny' Ice Racer, Very Clean, Hondaline Fairing, custom FT tire, will put in the 300R motor
'70 US90 'Ol'Girl" - Aquarius Blue... all original seat and tires. Resto project in the future
'85 ATC250ES-'Workin' Girl' CMP Footguard, Hondaline Mudflaps, Speedo, HL Lens, Block Heater, Work Light, Foot Peg Covers and Cooler Rack
'85 ATC70 - All Original
'84 Yamaha 225DX - Durablue +3" axle, DR motor, New Plastics, Foot, Hand and HL Guards.
'85 Yamahauler - Gun Rack & 'Nerf Bars'
'85 Yamahauler - Nearly together and restored
'83 Suzuki ALT125 - Pieces
'89 Suzuki LT-4WD - Token Golf Cart