Hi. We just bought our first home in march. right now we are insulating everything. the heating ducts in the unfinished basement/crawl are mostly unwrapped, but some have this weird stuff on them. our home inspector couldn't id (see image attached). Based on what i've seen online it doesn't look like asbestos, but i have no clue what it is. its dry and crispy and flakes at the touch. its textured. it almost looks like an old foam pad, but its too long for that. the house was built in 1953. should i just fiberglass wrap over the top? should i get it looked at first? thanks for any input!!