I know there are guys on here that will know more about these than I, but I will atleast get you started.
It is my understanding that the Amir line was the first attempt by Zildjian to compete in the entry/intermediate level market featuring any other formula than B20. I think these were like B12 or B15. For some reason I don't think they were B8. While some of their offerings since then have been pretty good, most (like myself) consider the 1st generation Amir to be Zildjian's best intermediate/entry level EVER. ....and the story goes that they all went downhill from there. This is seen when you discover/hear any AMIR II cymbal. This was a 2nd generation that fell way short of the reputation/performance/quality of the 1st generation. These 1st generation cymbals are not always easy to find, and those who have them generally are big fans of them and really cherish them (I know I do). The HH is very thin sounding (not thin, thin sounding), pretty dry, very refined. Of course, you have them right there and have surely checked them out by now. As far as I know, you do indeed have the 1st generation ones there - but I would like others to verify that. The Amir IIs were identified by the ink signia obviously showing what they are.
I have had a 1st generation ride, but was not very impressed at all. I actually think my 1st generation Scimitar ride from 1986 is a better ride than the Amir. I have never had any exposure with any Amir crashes.
My first exposure to any in this line was when I watched a jazz concert while I was in college at EMU - in about 1990. I approached the drummer after the performance because I HAD to know what kind of HHs he was playing as they had a great chick.
Years later (about 2 years ago) I was delighted to find a pair for about $50-60 (can't remember). Sometimes you can find something like that for a reasonable price like that, but it is not very common you find them offered - fairly rare as far as the market goes - as I suspect because the owners of them like them so much.
Great score - I recommend to hang on to them.
I know very little about the Impulse line. I think they were heavier and designed to compete with the Paiste Rudes.
John