Need to call a web service from PowerBuilder Classic 12.5

I have created a web service that is running on an IIS server. 

I need to be able to call this web service from PowerBuilder Classic 12.5.
This web service is used to store and retrieve PDF files from an imaging system.

I was able to create a Web Service Proxy in PB Classic using New -> Project -> Web Service Proxy and call the proxy using a SoapConnection.

Long ll_image_id, ll_StatusCode

ws_UploadImageResult l_uploadimageresult

SoapConnection conn

ws_service1 proxy_obj

Long ll_return

conn = create SoapConnection

ll_return = conn.CreateInstance(proxy_obj, "ws_service1")

try

  l_uploadimageresult = proxy_obj.SaveImage(ab_image_bytes)

  ll_StatusCode = l_uploadimageresult.StatusCode

  ll_image_id = l_uploadimageresult.DocHandle

catch (SoapException e)

  messagebox("Error calling Web Service", e.Text)

end try

This works unless my PDF is over 16K in size (almost all the PDFs are too big).

I then created a proxy object in PowerBuilder .NET using New -> Project -> WCF Client Proxy.
This created the chartswebproxy_ChartsWebServiceClient object. 

When I build the proxy project I get the chartswebproxy.dll and the chartswebproxy.dll.config files.

How do I get from creating the proxy object DLL to calling it from PowerBuilder Classic?

This is what I have tried:

I created a New -> Target -> .NET Assembly to reference the proxy object. 

I can see the chartswebproxy_ChartsWebServiceClient object in the Objects -> Custom class objects list. 

I have checked the three functions in the proxy and the wcfConnectionObject. 

I checked the Project -> Sign -> Sign the assembly checkbox but when I click the New button the SNK file is not created.

I know I need the SNK file to do the ildsam and ilasm calls.