Unfortunately, it isn't practical to offer a warranty.
Most of the classic cars I sell are entry-level or 'more affordable' models, and given their age, typically between 40 and 90 years old, age related issues, wear and tear and imperfections are inevitable.
It's unrealistic and unfeasible for me to conduct a complete inspection of every car before sale and identify every issue. Many issues arise simply due to age and general wear and tear. Replacing or repairing every worn component would also be impractical. Buyers should expect signs of wear and tear, past repairs, and age-related issues that come with classic cars, as these are part of their history and current condition.
It's impossible to predict if or when a problem may arise. Classic car ownership is a hobby, and buyers should expect to repair and maintain them as part of the experience.