I love Royal 10's - their design says early twentieth century typewriter, they are durable and last a long time, and at least until recently they were inexpensive, though compared with six months ago I get the feeling significantly more people are bidding on what becomes available.

Regarding the wobbly carriage - I own a 100 year old example which has a very wobbly carriage, but somehow it continues to type straight and level. This is definitely not related to the upper case/lower case misalignment. Could be somebody has been messing with the stop adjustment, could be some obstruction to carriage movement. In my limited experience I've already seen several examples where it is both, so I guess a common scenario is (1) notice alignment problem (2) acquire tyro knowledge about stops (3) attempt to adjust said stops, not realizing that something else entirely is blocking the range of carriage motion.

My tastes have turned to more recent machines because after you get over "Look ma, it types, it types!" and you might want to type something longer than Hello World you will have second thoughts about pounding a near antique for that long, even if your stamina holds up.

Sounds like the carriage L pieces are out of alignment. Try loosening the screws on them (Behind, lower part of the carriage), and slide them up until the are almost touching the carriage rail. You'll know what I mean when you do it.

I know I'm a little late to my own party here, but my Royal now functions perfectly, except for the slight misalignment between upper and lower case - but I'm not bothered by this.  It's been given a new ribbon, new feet, and nice wash and wax, and now she's ready for her next 100 years!

I'm really liking this one, now that I've gotten to know it better - it somehow just feels more personal writing on a machine of this vintage, even as far as typewriters go.