Please don't take my comment the wrong way, I was just having fun formulating with you. I also wanted you to find a spelt supplier for me.
Pre-qualifier, there are many around much better at conversions than me so I will leave that to them and instead explain where I would start.
If it were me I would start at 1 part Malted wheat to 1 part Pale or Pilsner. Assuming his wheat extract was 60% wheat and 40% Pale, he was closer to a ratio of 2 part malt to 1 part wheat. With those sweeter notes I'd throw in a bit of 20 or so Crystal or up the malt ratio.
He had 7# extract, using a .6 grain to extract conversion, that gives a bill of 11.5#. I could not get this to hit style in BeerSmith. 10.5 came just a hair above 1.056 vs. 1.052 as top end for style 15A.
5# Wheat Malt
5# Pilsner Malt
.5# Crystal 20
Pearle was hard in Beer Smith to as a high IBU contributor as a bittering so I dumped it. I know I can't get get it form my pretty well stocked LHBS w/o special order. Style is 10-20 IBU
Erdinger
Weizen/Weissbier
Type: All Grain
Batch Size: 5.00 gal
Boil Size: 6.00 gal
Boil Time: 60 min Equipment: Brew Pot (6+gal) and Igloo/Gott Cooler (5 Gal)
Ingredients
5 lbs Pilsner (2 Row) Ger (2.0 SRM) Grain 47.62 %
5 lbs Wheat Malt, Ger (2.0 SRM) Grain 47.62 %
8.0 oz Caramel/Crystal Malt - 20L (20.0 SRM) Grain 4.76 %
0.50 oz Hallertauer [4.80 %] (35 min) Hops 6.9 IBU
1.00 oz Tettnang [4.50 %] (10 min) Hops 5.7 IBU
Beer Profile
Est Original Gravity: 1.056 SG
Est Final Gravity: 1.014 SG
Estimated Alcohol by Vol: 5.36 % Actual Alcohol by Vol: 0.65 %
Bitterness: 12.6 IBU Calories: 43 cal/pint
Est Color: 5.1 SRM Color: Color
Mash Profile
Mash Name: Single Infusion, Medium Body, Batch Sparge Total Grain Weight: 10.50 lb
Sparge Water: 4.23 gal Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F TunTemperature: 72.0 F
Adjust Temp for Equipment: FALSE Mash PH: 5.4 PH
Single Infusion, Medium Body, Batch Sparge Step Time Name Description Step Temp
60 min Mash In Add 13.13 qt of water at 165.9 F 154.0 F