The Brian May album version, and his instrumental (electric guitar, strings, piano) version.
They are approx. the same length (give or take two seconds), and run and approx. the same speed (give or take little segments with tiny differences; nothing too problematic however).
I tried to combine the two with a bit of success; however, I don't have the neccesary experience or skill to do it to a satisfactory degree. For example, the mixing of the volume (some parts it would sound nice with less of the instrumental version, or in fact none at all, since it does on occasion clash with the acoustic guitar of the album version). Other parts the piano seems to echo a bit, maybe one track needs to be cut out. Anyway, I'm not sure about all the specifics, all I know is that it sounded very passable though not fantastic after I did a mix in about 10 minutes.
Perhaps someone else who has more skill than I could do a better mix...I think they make a nice combination.
I have done this before, although not on here. I simply mixed the two versions together, and the results turned out OK, but not particularly professional. I have been thinking of having another go at it, so maybe you will be in luck, but I can't promise anything just at the moment, therefore if someone else wants to have a go, please do!