KV6 oil leak on ancillary belt cover

[chris75]

I am in the process of fitting a new hydramount to my kv6 , and am puzzled by an oil leak onto the ancillary belt cover nearby . This oil leak has been there for well over a year now but is puzzling me as it only appears on the belt cover ; the adjacent castings , pulleys and the belt itself bear no evidence at all of oil . I have run the car without the cover and seen no trace of any oil anywhere at all . The only local source of oil is the power steering pump , which was a replacement a few years ago , and again I can find no evidence of a leak . I even wrapped the pump in a plastic bag to gather evidence , but nothing , and no apparent loss of fluid from the reservoir !
The oil runs along the edge of the cover but is not enough to drip off - just a damp stain . I can clean it off but it returns . I attach a few pics which I hope are good enough to show what I mean .
Anyone come across something similar ?
Whilst I am on , the hydramount I am fitting is the one for the kv6 but stands approx 6mm higher bottom face to top face than the old one . Is this to be expected after years of compression on the old rubber and a bit of oil loss ?