There is a Per Albert Sundin in the population register of Södermalm (on CD), a part of Stockholm city. He was born April 24, 1862 in Viby parish. There are two Viby parishes, in this case I would guess Viby in Närke province, Örebro county, is the right one. (The other one is in Östergötland province/county.)
On the same CD and in census 1890 there is a possible father: bricklayer and widower Johan Albert Sundin, born June 2, 1833 in Lerbäck parish, also in Närke province, Örebro county. In 1884 he was living with three children of his, all born in Viby parish:
Anna Mathilda b. April 1, 1871
Erland Fredrik b. Oct 27, 1874
Hulda Maria b. Oct 2, 1877
Hopefully, someone with access to the parish registers of Viby will verify that these are the persons you are looking for. If you don't get any further information here you can write Landsarkivet (Regional Archives) in Uppsala. You will find addresses and info in English at
www.ra.se/ula