Nice find, these items at aliexpress might be an option, although it does come at a price. It seems they only supply it as a 6 positions switch, while the 8088 has four flavours; 4 positions for the speaker selector, 6 for the rec selector, 5 for the source selector and 3 for the phono selector.
Now if you dive a little deeper into it, you will find there are a zillion companies at aliexpress offering the same items. That is ok, but mostly they do not have the faintest idea about what they are selling, any question about it is Chinesely politely ignored or comes with a counter question; how much should we send you? And even if you tell them you are not interested (anymore), this question will be repeated for a very very long time (so the dare devil that does take the leap and communicates with them better uses a throwaway e-mail address).
A three position switch is offered at taobao;
click, although it will not support the knob without adaptation.
Another consideration; these things come with the switch itself attached, this switch should fit the board of course and would need to have the same layout internally as the old one.
Anyway, personally I would try the repair option first.