Unsure about keeping this the HP one or if I should make aliases or something smarter

* Rounding errors:

2 4 -19.903 0 10.003 -19.903 0 -10.003
2 4 -19.838 -29.017 -10.004 -19.865 -29 10.003
2 4 19.92 -29.017 -10.004 20.009 -29.004 10.003
2 4 20.097 0 10.003 20.097 0 -10.003

* The seam in the middle has to be closed:

2 24 -.041 -58.675 -79.342 -.041 -62.65 -77.029
2 24 -.041 -53.975 -83.569 -.041 -58.675 -79.342
2 24 -.041 -69.492 -72.338 -.041 -74.592 -68.981
2 24 -.041 -53.977 -83.573 -.041 -58.677 -79.346
2 24 -.041 -62.652 -77.032 -.041 -66.558 -74.297
2 24 -.041 -62.65 -77.029 -.041 -66.556 -74.294
2 24 -.041 -66.558 -74.297 -.041 -69.492 -72.338
2 24 -.041 -49.392 -88.601 -.041 -53.977 -83.573
2 24 -.041 -58.677 -79.346 -.041 -62.652 -77.032
2 24 -.041 -49.39 -88.598 -.041 -53.975 -83.569
2 24 -.041 -69.49 -72.334 -.041 -74.59 -68.978
2 24 -.041 -66.556 -74.294 -.041 -69.49 -72.334

* Rounding errors also on the sides:

2 61 -19.473 56 -11.774 -19.646 56 -28.198
2 61 -19.665 56 47.49 -19.672 56 31.797
2 61 19.787 56 -48.334 19.885 56 -32.622
2 61 19.891 56 68.51 19.926 56 51.8

Fixed a misunderstanding regarding shortcuts

I need more information on the errors you refer to here. I can not see any issue in those areas. Care to elaborate a bit more?

* The cutout has to perfectly fit a 1x2x2. Your vertices need hard rounding:

1 47 0 -48 0 1 0 0 0 1 0 0 0 1 3245a.dat

2 3 20 -29 10 20 -29 -10
2 3 -20 -29 -10 -20 -29 10
2 4 -20 0 10 -20 0 -10
2 4 20 0 10 20 0 -10

* The seam has to be eliminated with:

2 2 -.041 -31.207 19.999 .041 -31.209 19.996

X=0 for both subs

* The part has to accommodate the LDraw system. In this case the cutout and the feet.

1 47 0 56 10 0 0 1 0 1 0 -1 0 0 3832.dat
1 47 -10 48 60 1 0 0 0 1 0 0 0 1 3024.dat
1 47 0 48 80 1 0 0 0 1 0 0 0 1 3023b.dat
1 47 10 48 40 1 0 0 0 1 0 0 0 1 3024.dat

2 5 20 56 68.51 20 56 51.865
2 5 1.3 56 50 18 56 50
2 5 1.3 56 70 1.3 56 50
2 5 1.3 56 70 18 56 70

Thanks! I will do the necessary adjustments

It might be worth adding a vertex or two at the back of the deer to smoothen the curve there, very point at the moment.

Ok, I have now done my best to learn from the comments and alter the model thereafter. Let me know if something still is off. Regarding the hooves I kept the inner part at 1.0 and -1.0. Not 0. I have the real part in my hand and they do not go all the way to the middle. Gap is gone in the middle and I added a few segments to the back