Implementing PrestaShop 1.7 API-Method; StockSet: Set stock quantity

We are looking for a Prestashop experienced programmer to implement the following task:

Implementing an API method to set the product quantity for items with advanced stock management. The customer sends an API-request from an ERP system to PS with the following structure:

StockSet?product_id=1345&warehouse_id=3&product_attribute_id=8072&quantity=999

Full Example URL:
https://www.example.xy/api/stockset/?product_id=1345&warehouse_id=3&product_attribute_id=8072&quantity=999&ws_key=APIKEY

This request should update the warehouse related quantity of the product but it no longer works after updating from version 1.6.x to 1.7.6.8.

We have already tried to rewrite the corresponding override, but due to a current lack of ressources we are looking for someone who can do this reliably. We are also interested in a long-term cooperation in this context.

Thanks for your Applications!