I remember getting help from my grandfather sending a mail to Denmark complaining that the rubber bands in some model broke, and they were not easily replaceabl

I remember getting help from my grandfather sending a mail to Denmark complaining that the rubber bands in some model broke, and they were not easily replaceable with regular rubber bands. So I got a reply back with some new rubber bands along with this book. The excavator on the front page was possible to build with my bricks and also a good build.