Of wheels and spokes on a CB450

n00b questions - be gentle!

I'm in the midst of working on my franken-450 (73 CB450 with a 500T motor). I have the official manual which states 18" wheels, front and back, but I'm pretty sure the front on mine is a 19" - the tire up front has a label of MJ90H19 - right?

I'm wondering about all of this because I'd like to put new spokes on - the old ones are pitted and nasty. Can I buy just any 19" spokes and lace them on? As to the rims, they're really green, rusty and nasty. Can I replace them with any rim of appropriate width and spoke count?

Since I'm trying to save cash, maybe I should just try to polish and paint the spokes and wheels instead... I'd really like new and chrome, but damn, new rims and wheels are expensive...