I made a post on the r/Libertarian subreddit about this because that's where you see the most posts/interest towards Marvin Heemeyer and his Killdozer - but it's a bit of a controversial subject and subsequently my post was removed.

https://en.m.wikipedia.org/wiki/Marvin_Heemeyer

This piece in the picture is to my knowledge the only piece that remains of Marvin Heemeyer's Killdozer that leveled sections of Granby in 2004.

Nearly a year after the event, the sheriff's department had the "Killdozer" destroyed. The first stage was handing it over to a machinist that removed the heavy armor pieces. Then it torn into pieces and taken by several dump trucks to scrap yards around the state to be melted. This was an effort by the sheriff's department to prevent anyone that praises Marvin Heemeyer as some sort of vigilante hero from getting their hands on any sort of keepsakes/souvenirs.

The final destruction of the Killdozer was on June 9th, 2005. My father was a videographer for Channel 7 and he invited me, 10 at the time, to come see. It was exciting seeing the big construction equipment tear apart a big hulking piece of bulldozer. Before they did final cleanup, the demo crew offered that I could grab a little piece if I wanted. I grabbed a bolt because it was all I could fit in my little cargo shorts. I promptly left it in my closet and forgot about it for the last 20 years.

Unfortunately, as they were trying to keep the whole demo of the Killdozer hush-hush, there wasn't much press about its demolition. We did a live shot from an undisclosed location for the morning news, but there weren't many pictures or anything else included because again, the Sheriff's department was worried that Marvin Heemeyer would continue to be branded as some sort of "F the government" hero.

After they cleaned up the last of the scraps, everything was quickly taken to be melted and recycled. I'll include anymore photos I can find from the time. It's only been as an adult that I realized the significance, so it's just been in a Ziploc all these years with the heavy dirt and dust buildup that was originally on it. If there are any experts on this type of equipment, perhaps you could tell me where it comes from on the original dozer.

I am very uncertain as to what to do with it. I've been in some contact with a YouTuber building a reproduction of the Killdozer and potentially might send it to him to have a piece of the original on the new build.

To my knowledge this is the only piece in existence.

Edit: I have a Google Link I can send people with a few photos I've dug up that you can DM me and I'll share