About 25% of the calls I get go start something like this. “I just inherited my (mothers, father’s, grandmother’s, aunt’s, uncle’s etc). It has a few keys that don’t work but I practiced on this instrument growing up and I really want my kids to learn on it too. Is there any hope for it?” So the quick answer is…likely yes! Many older instruments from previous generations of piano players are quite viable and will work for years to come. The biggest problem is usually the tuning. Pianos that haven’t been serviced for years are usually ¼ to ½ step flat (that’s 50-100 cents if you’re interested). Tuning it back up to where it should be isn’t a problem, but does take a lot more work than a typical tuning. It will also need another tuning in 4-6 months, as the tuning is unstable after this “shock therapy” of a pitch correction.
Regarding the keys that don’t work: most of the time the repairs aren’t a big deal and cost between $30-$100. It is often sticky, rather than broken parts that cause this problem, and freeing up the sticky parts isn’t extremely involved. If there are many keys that are sticking, this may require some extensive repinning, which can be a bit more expensive, but once again, nothing impossible to deal with here.
In a few cases, more extense work may be required, but rest assured I’ll lay out the options honestly and help you evaluate whether or not this piano is going to be worth spending time and money on. Far more likely is that your piano will be fine and will become a family fixture just like you remember from your growing up years.