Just rebuilt 3x Rollei 6008i battery packs using NiMH cells supplied by NOVAPHOTOGRAPHY on eBay.

First class service and instructions from battery seller.

Soldering was a bit fiddly and reassembly quite tight.
The plastic shield that prevents the spare fuse falling out is now much more difficult to move - tried using PTFE lubricant but didn't improve things much.
I'm not worried about that - I always carry a 35mm film canister in the bag with spare fuses - have never had to use one yet.
Had to make a small cutout on one of the plastic battery covers to allow the new battery tabs to fit.

Tools needed:

PH000x40 screwdriver (Wiha PicoFinish 261P)
Heatshrink insulation
Hot air blower (Butane hot-air blowtorch from Amazon - approx 8)
Heatsink thermal conduction compound (Maplin)
Craft knife to trim back the supplied heat-shrink insulation so I could solder the tabs

The batteries charge just fine in a Rollei Charger N - just remember to lift them out when the red light extinguishes after an hour and reinsert them for another hour to complete the charging.

Hope this is of interest / use.
Contact me if you need any further info or reassurance if you are embarking on a similar project.