Some sort of Lymantriidae caterpillar?
I think it's indeed a young, and possibly worn, specimen of Orgyia antiqua (also Rusty Tussock Moth or Vapourer, see also UKmoths). This species is relatively common in large parts of Sweden. However, the tufts and "tail" are usually more pronounced, but there is probably intra-species variation, and old, worn individuals can have sparser tufts. As you say, they are usually longer than 1.5cm but there is large variation, sexual dimorphism and younger larvae (early instars) are natually smaller.


(picture from wikipedia)

Swedish specimen:

( from http://krypinaturen.se/fjarilar-lepidoptera/nattfjarilar/tofsspinnare-lymantriidae/orgyia_antiqua_1878_20130626/)

Lymantria dispar is rather rare in Sweden and is only found in certain localities in the south (Blekinge, Småland coast) along with Öland and Gotland.