How to tell if my guppies are endler hybrids?

my guppies belonged to my uncle before he died, and I vaguely recall hearing once or twice that he had thrown a handful of endlers into the group just to see what would happen

the appearace of the fish seem to be split as such:

females with half black bodies and yellow black tails
males with half black bodies and fiery swallow tails (as in profile pic)

[unknown female appearance]
males with silvery bodies, bright orange and pink and black spots, with yellow/orange sword or double sword tails (with clear centers) the first sign of them coloring up is a yellow stripe in their lower tail.

most of the remaining guppies are juveniles, so its hard for me to tell what they will look like as adults. there are some young silvery females with darkening gravid spots, but no developed color.

however, one of the black and golds started this way, so there's no telling. they are about 3/4 inch now.

I can try to get photographs, but the young males seem to be so energetic, and my phone's camera isn't great. I'll add photos if I can get them.

 

had some luck! my most mature one stayed still for a moment!

 

had some luck! my most mature one stayed still for a moment!

Definitely looks like they have some endler in them. They tend to be smaller than guppies and will show some bold, randomly-placed orange and black.

 

Definitely looks like they have some endler in them. They tend to be smaller than guppies and will show some bold, randomly-placed orange and black.

they seem pretty small, but Ive no idea how old they are so I don't know yet when theyll stop growing! the one appears fully colored and is only an inch long. he seems so small!

the fiery finned fully adult male is basically the same size, even tho his pattern is much more guppy. I'm used to males being closer to 1 1/2, and am amazed at how small he is. I thought he was still slightly juvenile when I rescued him 2 months ago, but he hasnt grown a bit!

 

Honestly looks like a fancy/feeder guppy. Feeder males also stay smaller and have odd patches of color or even black markings. Without knowing what source he got them from that are less likely endlers and more likely fancy feeders - however guppies inbred several generations will produce smaller growing adults as well.

 

Just looking at those two pics it´s a tricky one to label them as being endler or endler hybrids. For yes, wildguppies or wildtype guppies (could be feeders) could look like this as well. A lot of people make the mistake calling wildtype or wild guppies endlers because of their size.
If you'll cross an endler and a guppy with another, in further generations (without culling) phenotypes may occur from both sides. If you'll keep randomly fancies together and after a couple of generations (without any culling), a number of them may revert to wildtype again.