Ibanez 77’ Rick copy! Could use a little help

Hi! So i’ve been playing bass for about four years now and i’ve finally decided to upgrade from my squier p. A friend of mine who knows a lot more about guitars than I do sent me a link to this 1977 Ibanez Rickenbacker for 500$ and I couldn’t resist. Now that I’ve got it I can’t stop playing it, I love the feel and tone but to be honest there’s some things I wouldn’t mind changing aesthetically. It’s currently missing a pickup cover and I wasn’t sure if I could just buy one of those off the internet and screw it on if anyone could help. Another thing is that the seller told me the knobs no longer fit after he installed 500k pots, so is it just a knobless bass now or are there variants of knobs that might fit it? Thanks for reading if you got this far and any help that might come my way