The AGDA 28 saddle on my Carlton still had its original nasty shiny black (cracked) varnish. I sanded it back using a marvellous 3M (320 fine) wet/dry abrasive which is bonded on to a flexible backing - lasts heaps longer than conventional papers. That brought back a nice natural dark tan colour. I lathered top and underside with saddle dressing (the Australian product - largely lanoline and beeswax based - is by RM Williams, who also make the world's best elastic-sided kangaroo leather riding boots) and left it in the sun for a day before giving it a buff with a soft cloth. Numb bum no longer! Much rubbing with said bum has imparted a nice semi-sheen to the leather.