[Whyman]

According to my manual you use the same bolts for the steel space saver as you say so you should be fine. To be sure I would fit one on the front and rear axle and make sure the wheel rotates freely.

My previous car was a Merc E320 CDi and the tool kit included a set of bolts for the steel space saver. They were shorter than the bolts for the alloys.

I suspect that on the Merc the alloy bolts were too long if fitted with the space saver and may have protruded too far into the hub and damaged the brake mechanism.