You can use the below instructions to slipstream updates to the SCEP clients. This process also should work for any future updates.
These instructions are for the 64bit clients, but you should be able to figure out how to create a 32 bit client using the same process.
Download Main standalone client:
Client version 126.96.36.199 direct link: http://wsus.ds.download.windowsupdate.com/c/msdownload/update/software/crup/2015/02/scepinstall_230274d8b20bbe30fb94a287fd82670af0309ea4.exe
Rename the file as needed e.g scepinstall_188.8.131.52.exe
Use 7zip to extract the exe contents to a folder “scepinstall_184.108.40.206”
Download the latest update 220.127.116.11 [May-2015]
Rename the update file and extract to a folder using 7zip, same as above.
Create a new folder called “SCEPClient_4.8.204”
From the client extract folder “scepinstall_18.104.22.168” copy the below files to the “SCEPClient_4.8.204” folder
Everything in the \amd64 folder
Copy the Required language folder and the below files from the root folder
Now slip stream the updates:
Make sure you overwrite the files when you copy the updates
From the extracted update folder “updateinstall”
Copy everything in the /amd64 folder and overwrite the old files
From the root of the update folder copy and overwrite the below files and folder
Final install folder should look like below.
You can now install it using the setup.exe
e.g setup.exe /s /q