You can order from here by mail: https://www.starelec.fi/advanced_search_result.php?keywords=tina&x=0&y=0

There are remarks on those 60/40 Pb wires "Only for professional use" (VAIN AMMATTIKÄYTTÖÖN). I called them and asked what that means. They explained that they're not allowed to sell the stuff "over the counter" because it's poisonous, but you can order it by mail order, pay it, and either pick it up at the shop or have it sent to you by mail. They won't check if you are a company or not.

Another source is https://www.kouluelektroniikka.fi/tuote/tyokalut-ja-tarvikkeet/juottimet-ja-juot..., but to order from them you need to have a VAT-number, ie. be a company. They also have those other parts.

Caps and other parts can be ordered from that first source as well (Starelec in Vaasa), from https://www.partco.fi/en/ or, as many does from Poland: https://www.tme.eu/fi/en/katalog/solder-wires-lead-based_113747/ They are fast and quite cheap, and has a huge stock! I use to order from them.

GL, Thomas

Little bit late, but...

The capacitors with a high voltage rating can be foud here:

https://www.uraltone.com/elektroniikan-komponentit/kondensaattorit.html