Finished Good Stock Uploading

Dears

Please see our scenario.

We are only creating Production Orders with respect to Sales Orders. But the production processes are not done in SAP like material issue, activity confirmation etc.

Now we have stocks of finished materials in the factory. We want to upload the same into the system and do the PGI and customer invoices.

I think we can do the initial stock upload transaction MB1C for this process with reference to Sales Orders.

I am little confused how that is going to affect the further transactions in SAP. Please provide your comments.

If that is OK, can we make the GBB-BSA inventory off-setting to Factory output GL A/c ?

Is this process is going to affect our Financial statements wrongly ?