I would go with the Celeron.
I have a Pentium II 300 versus a Celeron 300A,
the P2 can be OC to 350mhz, versus Celeron 450mhz.
In either Case, I have found my Celeron easily kick Pentium II's BUTT despite its huge Cache Size of 512K.
Pentium II has 1/2 divider on cache speed.
So your 350mhz = 175mhz Cache speed. versus Celeron's full cache speed of 300mhz on default, and 450mhz on Overclock. It really leaves the PII in the dust.
However, comparing the TWO is a MUTE POINT!
Both CPU LACK the support for SSE, you might as well throw both of them away and buy a new CPU/MB combo