Help figuring out origins of some words in a passage as reconstructed by an Italian Sappho anthology

Question

As I go over in this blog post (2.D.xxxiii), the text of LP 99a given by this Italian anthology has a few words I can't explain. Here is the glossary portion of the note to the text:

Now, the text is:

The translation reading:

… shortly after … the Polyanactid … … to the Samean (?) women … make to resonate on the strings … which the plactra receive banqueting friendlily with such people and lovably the harp vibrates, and the sound (penetrates) through the bones and, when it's inside, runs [through] the medulla.

So my question is: what is each and every word of l. 5? Or more specifically:

1. Where is περκαθθώμενος from?
2. What kind of word is δόκοισι, what does it mean, and what is its dictionary form?
3. What form of ὄλισβος should be read here? A singular to go with that participle in item 1, or a plural to translate as such as the translation does?

UPDATE

This paper indicates I was reading two words where there was only ὀλισβοδόκοισι, which I presume is from ὄλισβος and δέκεσθαι via some ablaut. This then means "which receive the plectrum" (since that is the meaning suggested by the paper in this context, though ὄλισβος otherwise always means dildo). So the correct reading to get the translation would be ὀ̣λ̣ι̣σ̣β̣οδόκο̣ι̣σ̣‹ι›, where, to fit my custom, I should use underlining to denote a guess at an unreadable letter, but that doesn't work here, so I used code markup instead. In fact, depending on the raw transcription of the rest of the word, I might need more underlines. Ah no, the paper says otherwise.

Sadly, the paper doesn't comment on περκαθθώμενος, which is why this is an UPDATE and not an answer.

This means that "which the plectra receive" is a stroke of genius where, in a fragmentary thing, you start a piece with a relative that subverts the SVO order to have the object before the verb, and there should be a comma after that, and after that ὀλισβοδόκοισι.

Answer 1

Just to avoid leaving this unanswered, @NickNicholas has traced the word at hand to the Doric (and Aeolic?) verb thôsthai, to banquet, thanks to a translation of "Una mitra per Cleis: Saffo e il suo pubblico", by F. Ferrari, which gives two uses of that verb as comparanda. The word is a hapax, in fact, the first attestation of this verb, which would be pĕrkatthôsthai (double theta or tau-theta as you please since, as @draconis commented, the choice was purely stylistical.