I have had few coffee machines in my time, so have three portafilters!! 1st one plastic ‘wood like’ can’t remember where I got it from !? Second one is de’longi ones, third is gaggia carezza deluxe. There’s no white plastic valve inside the gaggia filter, as it was broken you can buy on eBay. Finally the last metal single filter basket I’m unsure which model. Anyway you know they are expensive so selling for £30 which I think is reasonable.
eBay