1970 Constellation f300hz 198.002- Crystal and Crown Ref Numbers?

I've been super curious about these tuning fork watches for a bit now, in particular wanting to hear the sound and see the gliding sweep hand in action. Hard to pick which one but settled on the blue dial, stainless steel Constellation as my target. I quite like the splash of color with the red hand against the sector (is that the right terminology in this case?) blue dial. I've seen other variation with the Omega symbol pushed lower, like those as well but this one came up first. Picked it up via a quick, easy IG deal with CROADCO Watches. Watch was well represented with good communication, price was reasonable, and delivery from Columbia was very fast.
It's by no means a perfect example. Dial has a few blemishes to the finish, case is fair but showing it's age and probably a polish, original crystal but under a loupe a crack is visible on the sidewall at 6, crown has a small ding, and no service history. There is a watch maker's mark on the case back which appears to suggest a service in the 90's. Movement is clean and keeping excellent time (at least in the past couple hours of owning).
It was missing a case clamp and the date flipped at 1:00a. I've since added the third case clamp and reset the hands. In removing the crystal, the crack in the sidewall of the crystal was confirmed. I'd like to replace it but I need to hunt down a crystal. Can anyone share the Omega part number so I can hunt?
I'm also inclined to search for a replacement crown. Can anyone share that Omega part number too? And while on the topic, does anyone know if I can safely remove the stem to replace crown without removing module?
Finally, if anyone has advice on setting the time/date on this watch I'm all ears. So far I've read that the the time should not be set backwards, ever, not even by a minute.
And what's a thread without pictures??? It's on a spare Tropic until I find a suitable leather strap. What it came on was quite unsightly IMO.

Can anyone help with the crystal or crown reference numbers?
Thank in advance!!!

Also, if I remember correctly, don’t set the date between 11 and 3 o clock. Can’t help you with the part numbers, unfortunately, but I can offer pictures of an unpolished specimen. Wish you best of luck with your project!

Holy sharp! Do you need to handle that with chain mail gloves?

@Archer Is there a chance you can help me with the reference numbers for the crystal and crown? TIA!