the showa forks are the same outside dimensions on sp5 as well as strada. the lower stanchions on the SP5 are like a brown colour (i think?) and the lower stanchions on the strada are silver. note also that the strada showa forks are also fitted to the 92 model 851 and most 900ss'. the 97 model 900ss fe had the same looking forks as a SP5 but whether they shared the same internals i don't know.
also, the ohlins on the SP2,3,4,SPS which are fg9050 are 1mm larger at the top triple and 1mm smaller at the bottom triple.
if i'm wrong here i'm sure i'll be corrected, but i think that's right.