Heals mid-century large executive walnut desk (Send Marsh GU23)

Vintage, solid wood with walnut wood veneer. 77cm high x 127cm long x 71 cm deep. Bought new from Heals in 1956 by my father. Top surface sadly suffered water marks from a bowl recently ( see photos) but otherwise great condition for something used continuously for decades-( he mostly had it covered in piles of papers so the surface was never exposed!)