Delays from Cataloged dates are pretty much normal, Especially for engines.
Who makes it doesn't matter much in that regard.
LHS discount is not something I've run into but sounds like a shrewd LHS to me.
You get what you want, He doesn't have to front the price then wait for you to come in and pay. He gives you an incentive and you both benefit.
I'd stash the cash in a savings account and leave it there until the item arrives.
That's what I did for my Long Overdue Imperial Railking Northern, now I have a little interest in there to go with it. Supposed to be in next month now...