Oh wow, I think I owe you guys MULTIPLE beers!! I recently found out Karl didn't die as early as I'd previously thought, which then led me to his petition for naturalization. It confirms his 1881 birth in Ramdala, and says that his last residence in Sweden was Otenby (Ottenby), which I googled and saw is on the island of Oland, which you referenced in your post as the place the census reports him working in 1900!! It also says he emigrated from Kalmar, which I see is also in the region, in 1901 (unfortunately it lists his arrival date as Feb 1 on the Pennland, and I can't see that the Pennland arrived in Philly on that date....looks to me like he arrived in April. There's no certification of arrival with the petition, which is unfortunate).

Does the Swedish census list any further detail about professions or residence? I guess the next step is to sign up for a subscription to Arkivdigital? Is that relatively easy to navigate?