The most prolific source of humourous songs must be the Kipper Family and Sid Kipper
There is an immense amount of his stuff in the forum.
Another profitable source is Les Barker
Occasional flashes of comic song come from
The Yetties
Cosmatheka
Jasper Carrot
Pam Ayres
Harder to find are
Dave Summers
A group called Therapy The woman in the duo was Fiona Simpson
Bob Williamson

There is a lot of comic stuff in that lot

Regards

Fantum