BCD not PCD mmmm 84mm BCD .... I'll sort out the PCD .... Probably easier all round ..Are you sure it's 87? Not listed in the Sheldon Brown table
https://www.sheldonbrown.com/cribsheet-bcd.html
Typical smallest chainring for 144 BCD is 42 (part of the 52/42 double combo), there is a 41 but quite rare!
http://velobase.com/ViewComponent.aspx?ID=1F46D1C8-F7D6-4C09-949C-9CE7F0078D60&Enum=115&AbsPos=17
No it's a 9 speed ....Is it for a single speed / fixed?
Low budget bike build i'm afraid ..... thats why i'm after a usable 2nd hand one ..