A manufacturer could request the material, quantity, desired tolerances and technical drawing. Each enquiry would receive an identifier and file version. Staff would review feasibility before quoting, then retain the approved drawing separately from superseded working documents. The customer would see which version was used to prepare the proposed scope and price.
An illustrative example to adapt to your business. It does not represent a completed project in this municipality.
Does the website need to list every machine?
Focus on capabilities that help customers choose: accepted materials, dimensions and operations. An equipment list can support those details when someone is responsible for keeping it accurate and current.
How can the wrong drawing version be avoided?
Show the filename and version in the enquiry summary. A new attachment should pause the previous approval until the team responsible for preparing the quote has reviewed the change.