How much value can improvements add to a rental?

[Phat Dao]

How much value can building a garage add to a property? I've found a rental property that is a 4B/1.5Bath/No garage but there is parking at the rear of the property with footings to build a garage. It is currently sitting on a corner lot from a local college. Currently renting at $1300, asking price is $159,000. It is an older home built around the early 1900s so everything is all natural wood. How would you go about adding to the value of this home if you were to purchase it? Would you switch out the flooring for LVP and update everything so it is more modern or would you leave it as is?