Hi,
Sorry for delayed response. I understand that the Material type UNBW should now be non-valuated and you can uncheck the Value Update field in SPRO.
Look into the following SPRO--> Logistics General--> Material master--> Basic Settings--> Material Types--> Define Attributes for material Types--> Select your material type and click on Quantity/ Value updating folder--> Uncheck for your specific valuation area (s).
Check the Material Detail type now and remove the FI and Costing views.
Remember, before you do this activity, it is preferred to remove the stock of the materials in question either by consumption or by other method as suggested by business only after which you should touch the configurations.
For changes in number ranges in 91* series I am not sure of your requirement. could you please elaborate please?
Regards,
Bhaskar