At the risk of being flamed for daring to post something related to SW..
Frank Cathell and Lou Blasco have reverse engineered the famous
Universal Radio RIT modificaton for the Kenwood R2000 SW receiver.
It is not really RIT, but makes the BFO tuneable and is a very good
mod for any R2000 owner who does FSK or SSB work.
Details can be found at:
http://www.qsl.net/kc7bum/narrow-wide-filter-mod.html
There is an entire site devoted to the R2000:
http://www.qsl.net/kc7bum/

The modification is simple and reversable and took less then an
hour to install.

Terry