You may want to run this calculator and see how off you may be, and adjust from there.
Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators

 

you cant just cover ports, the sealed volume size of a box for a sub is up to 50% the size of the ported version, like my JBL takes 2.25 ported, but only 1.11 CF if i go with a sealed enclosure. but that does look some what small.

I mean you did an amazing job, no doubt it looks good, you might be lucky but you're def going to want to look at the calculator linked above to see what you should be doing. porting can get complex depending on how you do the bends, that changes the tuning, as well as the length of the bends, or width and depth, it all changes how the sound works.

 

He might be able to do exactly that, depending on the internal volume of each chamber. It sounds like he has no clue what that is though so it would be a crapshoot for sure. For his sake, I hope he made one hell of a guess cause glasswork that good would hurt to have to scrap.

 

he should block them at the back of the port, or he'd have some air pockets that could create distortions. though the navis woudln't notice

 

What's a "navis"? I've never tested this method so I can't call it...but it sounds like it makes about as much sense as doing 45's in a sealed box.