How did The Prototype, AKA Ollie, obtain the parts of the different toys?

Jester Upper Body: It's likely that Ollie was turned into a Jack In A Box, and separated himself from the box, in search of a new, and better bottom half.

Mommy Long Legs Arm: Towards the end of Chapter 2, The Player traps Mommy in a grinder that ultimately meets her demise. Whilst being crushed, she screams "DON'T MAKE ME PART OF HIM, YOU CAN'T DO THIS TO ME" Mommy fears The Prototype, but not because she's much older than him, but rather, she feared him due to his incredible intelligence. She knew that if she was to die, that Ollie would find her and fuze her into himself.

Huggy & Kissy Arms: At the end of Chapter 4, Krissy Missy's injured arm breaks off when using it to save The Player. When he arrived at the scene, Ollie collected the arm. As for Huggy, we know he lost part of his left arm, but not all of it. Ollie is seen to have an intact Huggy arm, from a different Huggy Wuggy.

Mechanical Bottom Body Half: Sometime during Chapter 2 or 3, Ollie discovers a large claw on the celling, one with razor sharp claws, made for picking objects up incredibly easy. Ollie rips the clw off and attaches himself to it.

Captnap's Fur, Ribcage, and Red Smoke Canisters: At the end of Chapter 3, Catnap accepts his death and has his ribcage displayed on the front of Ollie, Whilst his fur ended up on the back as a sort of coat. Ollie also took the liberty of retrieving some Red Smoke canisters in case he needed to make anyone hallucinatinate.

Lily Lovebraids: At the end of Chapter 5, Lily Lovebraids is crushed by a fake cloud. It's likely that Ollie returned to her area and will wrap her endlessly extending hair round his mechanical body to reach place his other arms can't.

How The Prototype Fuzed The Other Toys With Himself