Inquiry about Used Steel Structure Shed Building and Fabrication Workshop

We are looking for reliable suppliers of used steel structure shed buildings and steel fabrication workshops. The structures should maintain good quality despite being pre-owned and must comply with ISO standards. Our current requirements include:  
- Durable steel construction materials  
- Flexible workshop fabrication solutions  
- Certified pre-owned structures  

We need suppliers who can provide various options for different operational needs. No specific dimensions or budget constraints at this initial stage. Please share your available inventory and certification details.