Hi I'm the Sue Dent that transcribed the marriage record.
I've had a look for Elizabeth's baptism in my records & I can say that she wasn't baptized in Talland, Lansallos, Pelynt, St Martins by Looe or any of the Looe/Polperro non-conformist Chapels.
"Tancreek" is actually Tencreek, not far from Talland & just off the main road between Looe & Polperro, it's of interest to me because my great-grandparents lived there in the 1930s & 40s & whilst my grandad was serving in WW2 my dad lived there too.
BTW there isn't a Record Office in Liskeard & unfortunately many of the family history resources that the library used to hold have been moved (apart from the Cornish Times Archives & censuses local to the Liskeard area).
For births & marriages it's probably best to apply to the Registrar at Graylands, Dean Street.
http://www.cornwall.gov.uk/index.cfm?articleid=6261