FIRST decoction, oaked doppelbock recipe critique/help needed!

Never done a Decoction mash before. Please critique this - I really want to make sure I get this right (and not just the decoction part - feel free to tear up the recipe itself if you see fit). I have some questions below as well. Here is the recipe:

malt and fermentables
% LB OZ Malt or Fermentable
37% 7 0 Vienna Malt
32% 6 0 Pilsner (2 Row) Ger
16% 3 0 Munich Malt
5% 1 0 Dark Munich
4% 0 12 Caramunich Malt 70L
3% 0 8 Melanoiden Malt
3% 0 8 British Crystal 135-165L
Total 18 12

Original Gravity
1.082
(1.073 to 1.085)
Final Gravity
1.022
(1.019 to 1.024)
Color
20° SRM
(Light Brown to Medium Brown)
Mash Efficiency
60% (I know this is low, but I want to err on the side of caution - especially since I got 65% with my last high gravity beer, which was single infusion)

Batch size 5 gallons
7 Gallon boil for 2 hours

hops
use time oz variety
Boil 90 mins 1.0 Mount Hood
Boil 15 mins 1.0 Mount Hood

Bitterness
5.0 HBU
23.5 IBU
ƒ: Average
BU:GU
0.29

Alcohol
8.0% A.B.V.
6.2% A.B.W.
Calories
271 per 12 oz.

Yeast
WLP 833 German Bock Lager

Misc
Approx 10 days with 2 oz oak chips in secondary before bottling

Brewing Process
Hochkurz Double Decoction Method

used: decoction volume = total mash volume x (target temp - start temp) / (boil temp - start temp). Also, upped all volumes by 20% to be safe on hitting temp.

1) Strike in to mash temp of 133F (6.25 gallons at 145F). Wait 30 minutes.

2) Pull (thick) decoction (1.25 gallons). Heat to 160F, rest for 20 min.

3)Heat decoction to boiling. Boil for 15 min.

1 HR 30 MIN POINT

4) Return decoction to mash for rest at 146F for 30 min.

5) Pull decoction (1.75 gallons). Heat to boiling for 10 min.

2 HR 30 MIN POINT

6) Return decoction to mash for rest at 160F for 60 min

7) Pull (thin) decoction (1.66 gallons) and bring to 185F before returning to mash for 10 minute mash out.
UNLESS - anyone can tell me how much water and at what temp I would need to add to reach 170F for mash out so I don't have to do another decoction.

4 HR POINT

Batch Sparge with 166F 4.25 gallons of water to reach 168F for 20 minutes.

Boil for 2 hours

LASTLY - this is my first lager. I have the ability to control temp at lager temps, but I am unfamiliar with how to lager a beer. Primary will be at 48 and slowly bumping it up all the way to 55 to finish out over a 2 week or so period I assume (correct me if I am wrong). How long do I lager this and at what temperature though?

also, thanks to the kaiser - your posts, videos, etc. are expansive, well explained, and incredibly thorough. major props.

Sounds like you got it. Something I've done is graduate the inside of my mash tun. For the most part it takes pulling a third of the mash for the decoction to raise the mash to the next sach rest or sach to mash out. Having the tun graduated allows me to quickly do this.

As far as just adding hot water instead of using a decoction for the mash out it can be calculated with brewing software. Or just boil up a gallon or so of water and slowly add to the mash until you reach your temp. Figure up how much was actually used and you have your answer. I prefer to express my water as a quart to 1 lb of grain ratio.