The two references rcboater mentioned are excellent. The definitive source on French ships of the line, however, is a set of four volumes by Jean Boudriot collectively titled
Le Vaisseau de 74 Canons. It's available in an English translation by David Roberts.
The Boudriot books are classics. He reconstructs a typical French ship of the line in every conceivable detail, and explains how every part of it works. The first volume covers the design process and hull construction. The second deals with the guns, deck fixtures, and fittings, and the third with the spars, sails, and rigging. The fourth volume is a wonderful discussion of life on board the ship, and the organization of the French Navy. All four are illustrated with Boudriot's own drawings - hundreds of them. His drawings are among the most precise, and aesthetically beautiful, I've ever seen. Boudriot, who passed away a few years ago, was a master of the dying art of drafting.
Now the bad news. The books have been out of print for years, and when they were in print they were expensive. (I bought the first three volumes about 25 years ago for $75.00 apiece. I never mustered up the funds for the fourth one.) Used copies are scarce and even more expensive. But if you can locate a copy of any Boudriot book (he wrote several others on various French sailing warship types) in a library, or perhaps via the Inter-Library Loan service, it's a priceless source of information on model building.
I haven't looked at the Heller
Superbe for a long time, but as I remember it's a reasonably good kit. As a matter of fact I think I reviewed it for a British magazine a long, long time ago. As I recall its biggest problems were a lack of deck camber and a failure to indicate the edges of the hull planks. (My memory may be playing a trick on me here, but I think I remember commenting that the hull looked like it had been chopped out of one enormous log.) And the instructions, like those of so many Heller kits, were awful. I hope they've replaced the rigging diagrams, which were utterly irrational.
I'm no expert on French color schemes, and I don't have the Boudriot volume in front of me, but I agree that the broad gold stripe on the hull is nonsense. I think in general French warships were painted about like British ones were: unpainted, oiled hull planking, black wales (the thicker belts of planking near and above the waterline), red inboard works, and gold or yellow carved decorations. I'm having trouble remembering the colors Boudriot suggests for the masts and spars. When I get home this evening I'll try to remember to get the Boudriot book down and do another post.
I do remember that Boudriot's ship has a copper-sheathed bottom. Copper sheathing was introduced at about the time of the American Revolution. A ship of that period, therefore, might or might not have a copper bottom.
Rcboater's suggestion for rigging ratlines will work. I'll take the liberty, thogh, of suggesting another approach. The scale of 1/150 is a little small to rig ratlines to scale, but there's a pretty good substitute. Rig the shrouds first. They'll be pretty thick; the lower shrouds are among the heaviest lines in a ship. Then get get a spool of the thinnest thread you can find (try a sewing store, or a sporting goods store that carries fly-tying supplies), and a small, sharp needle. Cut a piece of thin, white cardboard (file card stock, for instance) to fit between the channel (where the bottoms of the shrouds are fastened to the hull) and the underside of the top (where their tops are secured). On that paper draw a series of straight pencil lines, about 14 scale inches apart. (On 1/150 scale that's about 1/16". If that's uncomfortably tight, apply the IFF: International Fudge Factor.) Place the card with the lines on it behind the shrouds. The lines indicate the spacing for the ratlines. Thread a length of the fine thread into the needle, and shove the needle through the first shroud where the first ratline is supposed to go. (If you're right handed, you'll probably find it easier to work from right to left.) Shove the needle through each shroud in turn.
At first that may seem extremely difficult, but give your fingers a chance to get used to it. You'll probably find that rigging that first ratline takes ten minutes or so. The second will take six or seven, and by the time you're done you'll be rigging at least one ratline per minute.
When you're finished, put a tiny drop of white glue at the spot where each ratline intersects the first and last shrouds. Let the glue dry thoroughly, then (this is the most nerve-wracking part) trim off the excess thread on each end. Use either a razor blade or a pair of extremely sharp, small scissors - and be careful not to cut any of the shrouds. If you do, you have to start over.
That may sound difficult, but once you get the hang of it it's not so bad. And ratlines rigged this way will look almost as good as if they were tied individually.
There are several possible explanations for rigging going slack. The most likely is that the thread is reacting to changes in humidity. If that's the case, the answer is to give each line a thin coat of beeswax. Sewing stores sell it in cakes, contained in nice little plastic holders with slots in them. Get in the habit of running each piece of thread through the groove in the beeswax holder. The wax also will smooth out any fuzziness in the thread.
Hope this helps a little. Good luck.