Up to now the answer has been no they cannot be modified safely to fit because then the lens would also fit the Leicaflex Standard and SL2, whose cam followers for the first cam would foul the ROM contacts.... but I think I've figured out how to do it with minimal modification to the hardware and full compatability while preventing hardware damage from bad lens/body combinations. I've run the idea past DAG and he says it ought to work. <P> The two differences between the SL flange and the R flange are a slightly larger inside diameter on the R flange and a slightly shorter bayonet lug on the body at the 12 o'clock position, with a correspondingly longer bayonet lug on the lens but (this is crucial) only on those lenses that would interfere with the SL's mirror. The bayonet lug size change was made beginning with the SL2 and the longer lug on the deep back-focus lenses prevents their use on the SL or Leicaflex Standard (where the mirror would hit the lens). <P> The only ROM lens I've had is the 80-200 f/4 (now a 3-cam lens), which has no mirror clearance problems. The flange that originally came with the lens requires the R-only larger inside diameter along with the shorter bayonet lug for the lenses with no clearance problems. If - a big if - Leica has beeen consistent about using the longer lug on the deeper lenses, then one could: <P> ) put the SL's metering cam on the ROM lens, leaving the ROM stuff and the lens' flange alone <P> ) enlarge the inside diameter of the SL's flange to R specs, leaving its 12 o'clock lug alone. <P> The modified SL would then accept any R lens that doesn't have mirror clearance problems and would still fail to mount the deeper lenses. The lens would still be incompatible with the Leicaflex Standard and SL2, so that the ROM contacts won't be fouled by these bodies' first-cam follower, but would fit the modified SL and (because of its retrofitted 2nd cam) meter correctly. Since the SL doesn't use the first cam it wouldn't damage the ROM contacts. <P> According to Don Goldberg the modifications to the lens and SL are both very simple. Note that this will not work with the SL2 or Standard - only the SL.