What is the location when the status is in service as coaching stock?
{'header': ['Vehicle Numbers', 'Vehicle Types', 'Livery', 'Location', 'Status'], 'page_title': 'British Rail Class 104', 'section_title': 'Preservation', 'caption': 'Preservation', 'rows': [['M50454+M50528', 'DMBS+DMCL', 'Blue', 'Llangollen Railway', 'In service'], ['M50455+M50517', 'DMBS+DMCL', 'Green', 'Churnet Valley Railway', 'In service'], ['M50479', 'DMBS', 'Green', 'Telford Steam Railway', 'In service as coaching stock'], ['M50447', 'DMBS', 'Green', 'Llangollen Railway', 'Under restoration'], ['53437+M59137+M53494', 'DMBS+TCL+DMCL', 'NSE/Green/Blue', 'Churnet Valley Railway', 'Stored awaiting restoration'], ['M50531+59228+53556', 'DMCL+TBSL+DMCL', 'Green/Blue', 'Telford Steam Railway', 'Stored awaiting restoration']]}