Hi, the Frame, Silvertip 30 from End of Nineties, is OK-ish, but the Grisley brand was just one of the brands used from Cycleeurope Group (Peugeot, BH, Gitane and others) after they have hired Peter Grisley (doing nicer bikes for Easton, Reflex, Look and Peugeot before).
Grisley is most know for the "Mega" series, an bike design with very oversized tubes and a bended top tupe - mono stay. To me, simply ugly looking...
Grisley bikes have been most likely produced by BH in Spain.
The rear wheel is from an bit of iconic socalled system wheelsets shimano has launched roughly 2003.
The all look special with a reduced number of spokes, Lx WH-M765 - to me the one used in that bike -, and XT type WH-M765 are pretty strong, but not very lightweight. Xtr variant WH-M965 is light but has a bit of flex.