This is the best master we have found and what we use on all the cars that come through our shop.
Ours has the correct, original screws holding the top in place, as well as the correct, original metal cap. The plastic caps you see on many aftermarket replacements are not correct and easy to strip if you over-tighten. Metal capped masters are the way to go!
This product has a 7/8 bores just like the stock master. We use this master on both disc and drum brake cars. Some people like to use a 3/4 bore master when changing to front disk brakes, but we prefer 7/8 for both drum and disk, primarily because we find the 3/4 bore master makes the brake pedal too spongy. Whenever 3/4 bore master equipped cars come to our shop, the pedal feels too spongy. I have used a 7/8 master on Gumby with disc brakes since 1979, and prefer the quick and firm pedal action of that set up and I believe you will too.
This is a great quality direct replacement for your old leaky / worn out dual master. We have had good longevity with this replacement and have field tested it on many Sprites.