The year is 1971 and the US Mint is about halfway through their short run of "S" business strike cents (1968-1974). This short run of 7 years are the only dates that businese strike Memorial cents are made in San Francisco. It is a nice little set to build and can be done rather inexpensively, even in high grade. The one in photo is graded Mint State 65+ Red by @pcgscoin. The "+" signifies that it has above average eye appeal for the grade. There is an element of grading that is subjective but it is mostly based on technical factors such as amount of wear or marks. Therefore you sometimes get coins that stand out and have an appearance of a higher grade but are held back due to a techincal reason.