Lost book title & Author

[chun]

Can anyone tell me the title of a book I was loaned back in the late '70s please. The storyline was about a man that worked in a factory (in England) for years making a part on a production line. One day he decides to go off into other areas of the factory with the intention of finding out two things,1- where did the part he made fit in the finished article and 2- what was the complete article. After years of making this part he didn't even know what the end product was. The next day he takes a packed lunch and starts his 'adventure' through areas of the factory he had never seen before...all different production lines making parts for the same article. He meets with different people...some kind and some hostile towards him. My last memory of the story is when he ends up in the basement and things go a little bizarre (if you have read the book you will know what I mean).
Sounds odd but at the time I was enjopying the book. Another vague recollection is the title I think was the main characters name, something like 'Mr???? day out' ?
If anyone recognises the story and let me know the title I would be most grateful. Thanks

[filobeddoe]

Pretty sure that is Smallcreep's Day by Peter Currell Brown, a seventies classic!