Høgger'n's grandfather died as a result of his Time Travelling
Hence why the magical glove was hidden away. One possible scenario: Høgger'n's grandfather tried to go back in time to meet William Shakespeare, but because of some problem that threw him off his coursenote , he accidentally went to 1349 instead. He quickly realized something was wrong and went back to his own time period, but fell ill a few days later. This, along with several other time travel mishaps, made him conclude that the glove was too unstable and dangerous. He hid it in a guitar and planned to dispose of it properly once he had recovered. However, he never got to do it because his condition deteriorated and the disease eventually claimed his life.
Aspic and Ruslebiffen are Obfuscating Stupidity
They try to appear stupid to hide the fact that they're planning to take over Blazerfjell. Building the machine seems like a great way to ruin the facade, but they're counting on everyone assuming that they actually stole it from someone and claim they built it themselves.