Great detective work on finding the 1858 marriage of James Ling in Pancras at Ancestry! Sometimes the information comes slow, but when it does finally, it's exciting to know another link has been established in the long chain of genealogical events.
Based on the information you provided in your latest communication, I believe I found the marriage index for James Ling at the FreeBMD website at: http://freebmd.rootsweb.com/http://freebmd.rootsweb.com/
The indexes at FeeeBMDfor this time period in the civil registration scheme do not list who married whom, but based on the 1881 census, and the 1871 census I found for James and his family (more on that later), I'd guess his wife was Honora McAuliffe.
The index below shows six names, three males and three females, but again does not twine them with known partners.
The full marriage record for James and Honora can be found on Volume 1b, Page 248 of the General Register Office (located in Southport) marriage records. If you order the marriage record from the GRO, include the Volume and Page Number as you'll save a few quid on the cert itself.
I'm not sure if you've ordered certs from the GRO before, but you can order them electronically and pay for them using a credit card. You can also order certs by post. The website for the GRO follows:
As mentioned earlier, I found James, "Hannah," and their children in the 1871 census living at 4 Suters Building, civil parish of Pancras, Marylebone.
Pete, this census enumeration appears to state that James was born in County Waterford and that Hannah was born in the County Cork.
Instead of trying to delineate the information in the census, I'll send you a copy of the actual return so that you can see it for yourself and also place it in your Ling genealogical records. I found this census at the subscription Origins.net website.
If you contact me at firstname.lastname@example.org I'll get the census out to you this weekend.