Seeking feeback on AG to extract attempt

Found this for my favorite German beer, a Mahr's Brau Ungespundet hefetrub. "Hefe" means yeast. "Trub" has the same root as trouble, turbulent or turbid, and refers to the yeasty cloudiness.

"It has an original gravity of 12.5 Plato (1050), is made from pale and Munich malts (beer color 20EBC); with a single mash at low temperatures; hopped with Northern Brewer and Hallertau Tradition (36 units of bitterness), bottom-fermented with a local yeast; and lagered for eight weeks at 0-1C. It has has an alcohol content of around 4.1 percent by weight, 5.2 by volume."

Here's my attempt at a conversion to extract:
4.5 LBS Alexander's Pale LME
3 LBS Briess Munich LME
1.2 LBS Briess Bavarian Wheat DME
.75 oz. Northern Brewer @ start of boil
1 oz. of Hallertau at 30 minutes
1 oz. of Hallertau at 5 minutes remaining
Wyeast Bavarian Lager Activator

Thoughts?

Hmmm...why the wheat? A low-temp mash on the original AG version would make for a thinner-bodied beer....the wheat extract will bring in a lot of dextrins that will thicken the body. If you're only adding the wheat for head formation/retention, I'd suggest considering smaller amounts of CaraFoam or CaraPils instead.

I haven't entered this into BeerSmith or anything...have you run it through some software to ensure your OG/IBU/etc. numbers line up?

Good point on the wheat, thank you. I was thinking wheat for the cloudiness.

I have not used any software for this, or ever for that matter. What's a good one to try?

In BeerSmith, this recipe results in the following (for a 5-gallon batch):
Estimated OG: 1.063
Estimated FG: 1.015
Estimated Color: 10.5
Estimated IBUs: 33.2
Estimated ABV: 6.25%

You are currently way too strong and too light in color, although bitterness is close.
You mention this being your "favorite German beer"...what is the flavor/aroma profile?

Based purely on the description quoted above, this is what I would come up with to start:

3# Weyermann Munich I (7.1 SRM) (flavor)
3# Weyermann Pale Malt (3.3 SRM) (for diastatic power)
1#10oz Dark Munich (~37.5 SRM) (color and flavor)
1# Briess Carapils (1.5 SRM) (for head and body)
4.8oz Weyermann Carafa II (415 SRM) (for color)
=============================
Mash the above at 149*F for 75+ minutes. Sparge.

Hop as noted above:
.75oz Northern Brewer @ 60 minutes
1oz Hallertau @ 45 minutes
1oz Hallertau @ 5 minutes

Pitch Wyeast 2124 Bohemian Lager yeast (much lower flocculation)
Ferment 2 weeks @ 52*F. Bottle and lager for 8+ weeks @ 33*F.

BeerSmith estimates this recipe as:
OG: 1.050, FG: 1.014, Color: 19.9, IBUs: 36.7, ABV: 4.7

Awesome, thanks for the help. Will let you know how it turns out.