WGA's "The German Sentries" kit doesn't initially seem like the best candidate to build an army from.
But I found the perfect list for them.
The 325 Sicherungs-Division/Defense of Paris list:
From the Campaign D-Day US Sector:
This list and the WGA German Sentries kit really compliment each other.
The Sentry kit has separate gorgets so you can build as many Feldjagerkorps as you want.
I would mostly use the bodies with low boots and gators to represent these veterans.
I would mostly use the bodies with jack boots to represent the rear echelon "Alert" troops who have been pulling sweet duty in gay Paris for the last 4 years. (Jack boots were far preferred by most German Soldiers and occupation troops would have definitely held onto them).
Finally the WGA kit lets you build an excellent looking Officer.
Here is the 500 point list I came up with. This is only using models and options in the kit.
The keen eyed will note that above is 31 models. To hit 500 points I had to use one dog model who is listed as a Feldjagerkorps member. I think the submachinegun does a good job of representing the dogs close combat capability. I would personally not shoot the dog's SMG in game.
Alternatively stealing 2 or 3 Panzerfausts from a Panzer Lehr kit would make a more well round force and hit 500 points without using a dog mini.
It's an interesting list with weak units and veterans. The Feldjagerkorps "Get Back In The Fight" rule actually creates a decent synergy. The Feldjagerkorps should be able to close and seize objectives. The "Alert" troops might be able to hold down objectives.