You can drive by the Melrose Towers on Melrose St. The Franklin Manor at 180 Green St., Melrose Place at 340 Main St., the following are decent size buildings but not over 50 unites. Probably 30+ units in these. Villa Cordoba on Albion St., Webster Wilows on Pleasant St. , and Station Crossing on Willow St.
There's a new project being built on Washington street. I don't think it will be quite 50 units but will be more than 20. Great location if you want to be near the t. Not so great if you want to be near Main street.