Closest I came to finding this online was the SDK for 2.1, in which all 68k support had been dropped (for Mac OS 7.6.x & PPC Macintosh only).

I did find a copy of the version 2.0 runtime but not the SDK. It would install & run on '040 Mac & PPC.

One possibility, if an online version of the version 2.0 SDK can't be found, would be to locate an Apple Developer CD circa 1997 - 1998, which I would think, should carry version 2.0 of it.

[Edit] The SDK file if it can be found, will have the name "MRJ_2.0.1_SDK.sit.hqx" or similar. I think this is the final of the version 2.0 series that can also run on 68k Macintosh.

There is a Wayback mirrored page here of the Apple Developer's download page for"MRJ 2.0 & MRJ SDK 2.0.1", describing version 2.0.1 including download links to the archives (FTP links and sadly, not available).