Tim,
I have built the libs using hbmk2 this way:
1. I have downloaded this file and installed it:
https://sourceforge.net/projects/openssl100g/files/Win32OpenSSL-1_0_0g.exe/download
2. Open a cmd window at c:\harbour\contrib\hbssl
3. set HB_WITH_OPENSSL=c:\OpenSSL-Win32\include
4. if exist "%ProgramFiles(x86)%\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" call "%ProgramFiles(x86)%\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"
5. c:\harbour\bin\hbmk2 hbssl -comp=msvc
Four libraries were built: hbssl.lib, hbssls.lib, libeay32.lib and ssleay32.lib
Here you have them:
https://bitbucket.org/fivetech/harbour-xharbour-builds/downloads/harbour_32_hbssl_vsc2015_20160429.zip