All I have is a dip belt, some plates, dip bars and a pull up

>>42513009
Before anyone asks, I got all this stuff from an uncle. Basically pass down equipment.

Enough to build and maintain good muscle?

you can build a muscular physique with weighted dips and pullups 100% guaranteed

but like anything else you need to get strong at them. If you can do those exercises with 50% of your bodyweight added to the dipbelt you will be jacked

your legs will lack though but hey just never wear shorts

>>42513023
also forgot to note your delts will lack a little bit so maybe buy a dumbell handle and do dumbell presses and rows