Hi All
Many thanks for sharing your experiences and help here.
Long story short, I had lid closure issues and diagnosed a bulging battery. I replaced the battery, which was only mildly bulging, and the lid still refused to stay shut.
Having read experiences here, I used the below link to learn how to remove the screen, and then clean and lubricate the hinges (which were very stiff) with silicon lubricant.
It worked, and the lid now closes perfectly again.
https://www.google.com/search?q=adjust+the+hinges+of+an+A+1398+15%22+macbook+pro&sca_esv=4fbe7c869920a6f3&sxsrf=ADLYWIIUUHRGJBrDd5OtLs5tdcmJeTE3lg%3A1736781785474&ei=2S-FZ_LEHOGhhbIPq8Pw6QQ&ved=0ahUKEwiylYCrgPOKAxXhUEEAHashPE0Q4dUDCBA&uact=5&oq=adjust+the+hinges+of+an+A+1398+15%22+macbook+pro&gs_lp=Egxnd3Mtd2l6LXNlcnAiLmFkanVzdCB0aGUgaGluZ2VzIG9mIGFuIEEgMTM5OCAxNSIgbWFjYm9vayBwcm8yBRAAGO8FMggQABiABBiiBDIFEAAY7wUyBRAAGO8FMggQABiABBiiBEjUpAJQjjZYpZICcAF4AJABAJgB7gGgAZwKqgEFMC44LjG4AQPIAQD4AQGYAgmgAsYIwgIOEAAYgAQYsAMYhgMYigXCAgsQABiABBiwAxiiBMICCBAAGLADGO8FwgIHECMYsAIYJ8ICCBAhGKABGMMEmAMAiAYBkAYHkgcDMS44oAebKQ&sclient=gws-wiz-serp#fpstate=ive&vld=cid:7c8e0e26,vid:g1u3mhRFdpg,st:0