Tube removed reads 3.00 / 3.25 - 18

the replacement I received under advisement is a 4.00 / 4.50 - 18, looking at online charts this seems to be the correct area making the tube fited the wrong size, that and a pillion could i guess be the contributing factors in it blowing?, (pinhole on the inner rim where the tube was rubbing in the rim centre)
I'd be grateful if someone can double confirm what I hope is correct based on my investigations and tyre place advice?
There was some corrosion on the rim, gave it a good going over with a brass wire brush and will clean down before refitting new tyre etc
Now the rim in question, though it has an 8.5mm rim hole and snap in valves standard size is 11.5, has the additional lip inside that you generally see on tubeless fit wheels and a channel down the middle, does this mean it would be suitable for tubeless use with a valve?
I'm still going to fit the tubes as I have them and would have to order and wait for valves but just curious, pic of wheel rim here.
