Green’s Dictionary of Slang

wonderful, excellent, often but not always of food .

1913		E.L. Warnock ‘Terms of Approbation And Eulogy’ in DN IV:i 19: scrumbotious. Same meaning as scrumptious [...] ‘Scrumbotious clothes’.
1932		J.B. Priestley Faraway in DSUE (1984).
1954		El Paso Herald Post 16 Mar. 1/5: [advert] The lusty trapper knew great whiskey [...] he called one ‘scrumdolicious!’.