The MIBs Files that Vendors have is only the information on their MIBs are the OID, the name and Description, and some automatic options such as Enumeration, IP_Address and whether it would be polled via Get, Get Next, or Get Table. The MIB Database that is shipped with all of our Products already include the Most Common Vendors as well as User Submitted MIBs from lesser known Vendors.
The best way to see what your device responds to, you can use our Toolset and perform a MIB Walk. Here is a link to our Engineer's Toolset
Once Installed go into Start> Programs> Solarwinds Engineer's Toolset> Classic Tools> SNMP Tools> MIB Walk, then enter in the IP Address and Community string, have it set to Standard and press Walk. You will then get a Full list of MIB Name, OIDs and Values returned for your Devices.
We also have User Submitted Custom Pollers here: Universal Device Pollers