I get really tired of people preaching "it's drying pool and there's only so much money to go around". That's nonsense. First off, you write letters and apply for every conceivable grant out there. Expect to apply three or four times to get some traction. That's how the game is played. You write for support from railway suppliers, leasing companies, companies which sponsor events, insurance companies. You write, write write, and individually sign as many as possible. Use postal mail when possible using letterhead stationary from a printer, but email sometimes is the only route - so use it! When you write, include numbers and clear photos which show action and progress while you wait for the contributions to come in. Explain, "when we hit a goal of $100,000 the new backhead and crown sheet will be installed (or whatever you are going to do)" and then work like hell to meet that goal in the stated time. If potential donors see work happening, they reassess their giving plans. DON'T WAIT UNTIL YOU'VE AMASSED THE TOTAL NEEDED. Use what you have to show you are moving in the correct direction. Do what you've promised and never siphon off donations to the locomotive to fund parties, carnivals, or mixers.
Look, people have money for what they want.
OBRM's concert approach is the most innovative thing I've seen in years. Kudos to those guys and whoever thought up that approach.
As far as "why a G5s?" Several solid answers: Strasburg shops, Strasburg Railroad, Pennsy design and family face which never got "the PRR beauty treatment". Pennsy style and design at it's best. RMPA is across the street - big draw to see a live PRR design engine. Pennsy fans are fanatics about their railroad. Could be moved wherever the K4s goes and double headed. Will make money for Strasburg and RMLI*. Biggest 4-6-0 ever designed, unique boiler in the USA, the artifact is put in top condition and operated, and eventually will be returned to Long Island for permanent display**.
*N&W 611 earned $20,000 on an operating day during the 2020 season, and this was the year Covid broke out. Do you really think a live PRR steam loco rebuilt by Strasburg, on Strasburg, would do less? Think again.
**I'll be dead by then, but placed in a climate controlled building for a technologically savvy world. What a leap of history and faith. Built before the depression and rebuilt 50 years after men walked on the moon arriving in another Long Island built vehicle.