Items Excluded ACNL 100% Speedrun

Furniture:

2017 Cake - DLC
24-hour-shop ABD - DLC (JP)
24-hour-shop counter - DLC(JP), Filly's RV
24-hour-shop model - DLC (JP), Filly's RV
24-hour-shop sign - DLC (JP), Filly's RV
Aries Rocking Chair - DLC
Aurora Screen - DLC
Barbecue Bed - DLC (JP), Filly's RV
Buffet Server - DLC (JP), Filly's RV
Capricorn Ornament - DLC
Cherry-Blossom Clock - DLC
Eraser Sofa - DLC (JP)
Fedora Chair - DLC (EU)
Fireworks Table - DLC
Full-Moon Vanity - DLC
Gemini Closet - DLC
Hagoita - DLC
Kadomatsu - DLC (JP)
Kagamimochi - DLC (JP)
Kimbap Plate - DLC (KOR)
Leo Sculpture - DLC
Libra Scale - DLC
Lotus Pond - DLC (JP)
Narrow Clock - DLC (JP)
Notebook Bed - DLC (JP)
Notebook Wardrobe - DLC (JP)
Pen-Case Chair - DLC (JP)
Pencil Screen - DLC (JP)
Pisces Lamp - DLC
Rainbow Screen - DLC
Rice-Plant Bed - DLC (actually obtainable from Medli's House)
Sagittarius Arrow - DLC
Sandbox - DLC (JP)
Sandwich Display - DLC (JP), Filly's RV
Scorpio Lamp - DLC
Set Square Table - DLC (JP)
Shaved-Ice Lamp - DLC
Slushie Machine - DLC
Soccer Goal - DLC (JP)
Soft-Drink Display - DLC (JP), Filly's RV
Steamed-Bun Case - DLC (JP), Filly's RV
Sticker Tape Liner - DLC (JP)
Sunrise Lamp - DLC (JP)
Taurus Bathtub - DLC
Top - DLC
Turkey - DLC (JP)
Virgo Harp - DLC
White Festive Tree - DLC (JP)
24-hour-shop banner - Filly's RV
24-hour-shop baskets - Filly's RV
24-hour-shop clock - Filly's RV
Fueki Chair - Holden's RV
Fueki Drawers - Holden's RV
Fueki Pot - Holden's RV
Fueki Stereo - Holden's RV
Fueki Table - Holden's RV
Donut Cushion - Filly's RV
Hot-Snack Case - Filly's RV
Shop Coffee Machine - Filly's RV
Shop Ice-Cream Case - Filly's RV
Sushi Bench - Filly's RV

Wallpaper:

Convenient Wall - Filly's RV
Notebook Wall - DLC (JP)
Fueki Wall - Holden's RV
Old Wallpaper (Doesn't appear in catalog)

Flooring:

Convenient Floor - Filly's RV
Notebook Floor - DLC (JP)
Fueki Floor - Holden's RV
Old Flooring (Doesn't appear in catalog)

Shirts:

24-hour-shop uniform - DLC (JP), Filly's RV
Blue Argyle Tank - DLC (JP)
High-Spirits Shirt - Holden's RV
Patched Shirt (Doesn't appear in catalog)

Hats:

Flamenco Hat - DLC (EU)
Red-Horned Hat - DLC (KOR)
School Cap - DLC (KOR)
Tam-o'-Shanter - DLC (EU)
White Police Cap - DLC (KOR)
White School Cap - DLC (KOR)
High-Spirits Hat - Holden's RV
Hibiscus Hairpin - Club Tortimer
Patched Hat (Doesn't appear in catalog)

Bottoms:

High-Spirits Pants - Holden's RV
Patched Pants (Doesn't appear in catalog)

Furniture (2):

Bottled Ship - Club Tortimer
Box of Chocolates - Club Tortimer
Ukulele - Club Tortimer (actually obtainable from Mitzi's House)
Whirlpool Bath - Club Tortimer (actually obtainable from either Chadder's or Broffina's House)

Dresses:

Muumuu - Club Tortimer
Patched Dress (Doesn't appear in catalog)

Shoes/Socks:

Patched Shoes (Doesn't appear in catalog)

"Filly's RV" & "Holden's RV" were both Wi-Fi only events in JP for limited time only. Much like the 7-11 items back when the game first launched in Japan.
All items in the list above were DLC in some sort, hence why they are impossible to obtain. There are some DLC however that is obtainable in Welcome amiibo in some character's RVs.