Back in the day, lowering blocks were standard equipment with a 16 rim. Pullback handlebars, backrest, windjammer, highway bars, bell bottom pants, oops I got carried away. The other parts are easy to remove, the 16" rim not so easy.
My sandcast had a 16" but the rolled 18" rim was on the PO's mechanic's drag bike. I had to buy it to get the rim. lol.