Hi H - are you reading your Farmers Weekly recipe book from 1940 again?
Scroggins are a mixed fruit and nut blend - though scruggins are the bacon bits as as BBWC has it.....you can use lard in a decent sweet cake of course - like a caraway seed cake for example, but I'd suggest its the fruit and nut mix you want for the Scroggins here - I have it as an old Welsh recipe....and guess the recipe got a bit mixed up in translation....
Interestingly - New Zealand has Vogels Cereals sold as having scroggin in it -
http://www.vogels.co.nz/Cereal.aspx but Vogel in the UK doesn't call it this....Wikipedia also has a desciption of scroggins as the fruit & nut stuff too....wonderful thing the internet..!