.30 carb???
Parker 51--My RCBS .30 Carbine die set was made in 1971--It produces cases with straight, slightly tapered, not stepped, sides. Which function perfectly in my M1 Carbine.
Might I suggest, before you go loading up any of those cases, that you try chambering several of the sized empties in your Ruger revolver to see if they indeed are sized down enough to fit. If the answer is "No go" you will have saved yourself some time and trouble.
If the answer is "go" then you might bell-mouth and load up some cases just with bullets, and see if they still chamber. Frankly I still would not use these dies--.30 Carbine cases are normally slightly tapered, with no shoulder. There is something funny going on here. Which means that unless you can find some very good explanation for the unusual sizing, I am advising you to abandon these dies and get a new set. Yes, that seems extreme. But...
I wouldn't go for the E-bay dies that you note--The seller has a little difficulty with English, and there appears to be some kind of gunk stuck to the threads of the bullet seating die. Finally, the seller (1) has named a price and is not taking bids, and (2) warns you that he is very slow on returns if you have a problem. None of these things inspires any confidence in me.
You can get a brand-new set of Lee .30 Carbine dies, with carbide sizing insert, from Midway, for $38.45 plus shipping. You presumably already have the shell holder. The "standard wisdom" is that you must lube .30 Carbine brass, even with a carbide sizer, unlike carbide-sized pistol brass. So for about 50 bucks or less you're good to go, and no more questionable, funny-looking cases. I have several sets of Lee dies, along with several sets from other makers, and the Lee dies are every bit as good, IMHO. And, Lee is VERY good on returns should any difficulties develop. IMX, their CS is second to none. Midway has several other brands of .30 Carbine dies, for around 46 bucks, if you're dead set against Lee.
That kind of money, to be sure you have the dies you need, would not seem like a deal-breaker.
Remember, we are dealing here with fiendish pressures, and hella hot gases, and you do NOT want these getting loose anywhere but downrange.
Just my opinion, of course. And please keep us posted, on your final results!