Is it a stronglight BB? It likely is. Measure the spindle. I'll bet you can mount a stronglight 99 and then you have good gearing choices. You need a special puller for those but the later ones used a standard puller. You can put up a WTB thread or keep your eyes peeled for a Peugeot UO 9 or 10. Those came with stronglight 99s. You can harvest the crank and flip the bike. I recently picked up a UO 9 for $49 so I could harvest the crank and flip the bike.