There are several key differences between ebrary and Ebook Central MARC records.
To match Ebook Central MARC deletes against your catalog records (that might be from ebrary, EBL, or Ebook Central):
The following are sample MARC records - an Ebook Central and two variations of ebrary records.

Ebook Central - sample "add" MARC record:
=LDR  01566nam  2200385 a 4500
=001  EBC102745
=003  MiAaPQ
=006  m\\\\\o\\d\|\\\\\\
=007  cr\cn|||||||||
=008  120721t19981988enkab\\\sb\\\\001\0\eng\d
=010  \\$z   97036299 
=020  \\$z9780198205623 (v. 1) Hbk
=020  \\$z9780199246762 (v. 1) Pbk
=020  \\$z9780191591778 (e-book)
=035  \\$a(MiAaPQ)EBC102745
=035  \\$a(Au-PeEL)EBL102745
=035  \\$a(CaPaEBR)ebr10578486
=035  \\$a(OCoLC)801969426
=040  \\$aMiAaPQ$cMiAaPQ$dMiAaPQ
=043  \\$ae-uk---
=050  \4$aJV1015$b.O75 1998
=245  04$aThe origins of empire$h[electronic resource] :$bBritish overseas enterprise to the close of the seventeenth century /$cNicholas Canny, editor ; Alaine Low, assistant editor.
=260  \\$aOxford ;$aNew York :$bOxford University Press,$c1998, c1988.
=300  \\$axix, 533 p. :$bill., maps.
=490  0\$aOxford history of the British Empire ;$vv. 1
=500  \\$aFirst paperback edition 2001.
=504  \\$aIncludes bibliographical references and index.
=533  \\$aElectronic reproduction. Ann Arbor, MI : ProQuest, 2015. Available via World Wide Web. Access may be limited to ProQuest affiliated libraries.
=651  \0$aGreat Britain$xColonies$xHistory$y17th century.
=651  \0$aGreat Britain$xHistory$yStuarts, 1603-1714.
=655  \4$aElectronic books.
=700  1\$aCanny, Nicholas P.
=700  1\$aLow, Alaine.
=710  2\$aProQuest (Firm)
=856  40$uhttp://ebookcentral.proquest.com/lib/mysite/detail.action?docID=102745$zClick to View

ebrary - sample "add" MARC record for a purchased title:
=LDR  01587nam  2200397 a 4500
=001  ebr2002565
=003  CaPaEBR
=006  m\\\\\\\\u\\\\\\\\
=007  cr\cn|||||||||
=008  010423s2001\\\\enk\\\\\sb\\\\000\0\eng\\
=010  \\$z   00045940 
=015  \\$aGBA1-23912
=016  7\$a0415191459$2Uk
=020  \\$z0415191459
=020  \\$z0415191467(pbk.)
=040  \\$aCaPaEBR$cCaPaEBR
=035  \\$a(OCoLC)264441546
=041  1\$aeng$hfre
=050  14$aDT33.5$b.S3713 2001eb
=082  04$a325.3$221
=100  1\$aSartre, Jean-Paul,$d1905-1980.
=245  10$aColonialism and neocolonialism$h[electronic resource] /$cJean-Paul Sartre  ; translated by Azzedine Haddour, Steve Brewer, Terry McWilliams.
=260  \\$aLondon ;$aNew York :$bRoutledge,$c2001.
=300  \\$axxiv, 200 p.
=504  \\$aIncludes bibliographical references.
=533  \\$aElectronic reproduction.$bPalo Alto, Calif. :$cebrary,$d2013.$nAvailable via World Wide Web.$nAccess may be limited to ebrary affiliated libraries.
=546  \\$aTranslated from the French.
=650  \0$aDecolonization$zAfrica.
=650  \0$aDecolonization$zAlgeria.
=651  \0$aFrance$xColonies$zAfrica$xAdministration$xHistory$y20th century.
=651  \0$aAfrica$xColonization$xHistory$y20th century.
=651  \0$aAlgeria$xColonization$xHistory$y20th century.
=655  \7$aElectronic books.$2local
=710  2\$aebrary, Inc.
=856  40$uhttp://site.ebrary.com/lib/yeshiva/Doc?id=2002565$zAn electronic book accessible through the World Wide Web; click to view
=980  \\$a071120$b52.5$cUSD$e52.5$fyeshivaT&F112007$g1

or
=LDR  01469nam  2200361Ia 4500
=001  ebr10570675
=003  MiAaPQ
=006  m\\\\\o\\d\|\\\\\\
=007  cr\cn|||||||||
=008  160627s2012\\\\enk\\\\\sb\\\\001\0\eng\d
=010  \\$z  2011041073
=020  \\$z9780199859443
=020  \\$a9780199859450 (e-book)
=040  \\$aMiAaPQ$cMiAaPQ$dMiAaPQ
=035  \\$a(OCoLC)796804029
=050  \4$aTD223$b.C47 2012eb
=082  04$a333.9100973$223
=100  1\$aGleick, Peter H.
=245  12$aA twenty-first century US water policy$h[electronic resource] /$cJuliet Christian-Smith and Peter H. Gleick ; with Heather Cooley ... [et al.].
=246  3\$a21st century U.S. water policy
=260  \\$aOxford ;$aNew York :$bOxford University Press,$cc2012.
=300  \\$axxi, 334 p.
=504  \\$aIncludes bibliographical references and index.
=533  \\$aElectronic reproduction. Ann Arbor, MI : ProQuest, 2016. Available via World Wide Web. Access may be limited to ProQuest affiliated libraries.
=650  \0$aWater-supply$xGovernment policy$zUnited States.
=650  \0$aWater-supply$zUnited States$xManagement.
=655  \4$aElectronic books.
=700  1\$aChristian-Smith, Juliet.
=700  1\$aCooley, Heather.
=710  2\$aebrary, Inc.
=856  40$uhttp://site.ebrary.com/lib/mysite/Doc?id=10570675$zClick to view
=980  \\$a130612$b59.95$cUSD$e59.95$f20130612cantor2$g1
=981  \\$bHSL - 20110492