Good timings but I think travel time can be reduced to 6 hours.
Also, another good slot for Mumbai - Pune - Solapur travel would be to start from CSMT between Deccan Express and Koyna Exp [i.e. between 7 to 8:30AM] since there is no intercity train to Pune in this time interval. Return journey can start from Solapur around 4:30PM to reach Pune at around 7:30PM and Mumbai at 10:30PM. Again there is no intercity train available after 6:30PM from Pune towards Mumbai