#1 and #2 are both from Showa Year 49 (AD 1974).
#3 and #4 are from Showa 46 (1971).
#5 is indeed a 1 yuan (dollar). It's also from "Year 49", but this is in the Republic of China calendar, which converts to AD 1960.
#6 is dated Year 2500 of the Buddhist era, which was AD 1957. However, these coins were struck with this year "frozen" from 1957 right up to 1987.
#7 is indeed a 1 baht, but it's not KM/Y# 74, it's KM/Y# 84. It is dated BE 2505, which converts to 1962, but, as with the 25 satang, it was struck with this frozen date from 1962 until 1982.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis