Thanks for all the help y'all. This is a very slow restoration on this deck as I don't have a lot of time to work on it. Got the idler pulley pulled off today and opened another can of worms. The tensioner spring disintegrated into about 4 pieces, the bearing seals also disintegrated when I tried getting them off, and the bearings are so rusted and pitted they are pretty much square. Does anybody know of a good source for these items? I found a used pulley on eBay but the seller listed it as working on a 42" and 38" deck. I will post the link, would this pulley work? I will still need the spring as well and I've had no luck as of yet on that front.
Pulley on eBay:
https://www.ebay.com/itm/255407265007