I'd looked at that James Pugh marriage the other day and dismissed it because the marriage register says bachelor for him. Also, his age on the census would make him nearly 10 years younger than Grace. But the place of birth would be rather a coincidence unless we're dealing with cousins.
I haven't been able to find a marriage for James & Grace & there isn't much online from that period which is why I suggested the archives.
There's a James & Mary Pugh having children baptised in Llanfair ar y Bryn at Pentre Ty Gwyn Independent before that marriage as well. Baptism for Mary dau of James Pugh & Mary Rees 5 May 1833 at Salem Calvinisitc Methodist church in Rhandirmwyn. These are on FreeReg.
Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb