I attached vending.apk for you (I had to rename to vending.zip to upload on DF). Download vending.zip, rename to vending.apk, and place it on the root of your SD card. The easiest way to move it to system is with Root Explorer (it is a paid app but definitely worth having if you want to easily play around with your phone's system files):
- In Root Explorer, navigate to /sdcard and long click on vending.apk and choose copy
- Navigate to the /system/app directory
- Tap the Mount R/W button on the top right
- Tap Paste it will ask you if you want to overwrite and you should select yes
- Scroll down to the vending.apk (the one you just pasted in /system/app), long press on it and select Permissions (you'll see 9 check boxes when you do this)
- Check the Read and Write buttons for User, and only the Read boxes next to Group and Others, then tap OK (once you're done, the read/write permissions under the app name should be the same as all the other apps listed (rw-r--r--))
- Reboot.
It can also be done with terminal emulator but root explorer is easier. If you want I can post the terminal emulator commands too.