Help identifying authenticity of a 1973 Omega Geneve

Hi All!
Very new here (both to the forum and the world of watches). Still going through a bit of learning, so excuse me if this is a stupid query.

I am looking at purchasing a vintage Omega for my wife and I came across this Genève from 1973 on Chrono24. With this particular example not having any original papers, and an original bracelet, how do I look for it's authenticity? I would love any help I can get.

The Ad:
Omega Genève
$482
https://www.chrono24.com.au/omega/omega-geneve--id48187614.htm?SETLANG=en_AU&SETCURR=AUD

The description:

Condition : Pre-owned - ExcellentThis item has been previously worn; however, it is in excellent condition. Any signs of wear should be shown and described in the seller’s listing. See all condition definitionsopens in a new window or tab

Brand : OMEGA

Band Color : Silver

Band Material : Stainless Steel

Band/Strap : Bracelet

Bezel Color : Silver

Case Color : Silver

Case Material : Stainless Steel

Case Size : 21 mm

Case Thickness : 8 mm

Customized : No

Department : Women

Dial Color : Silver

Display : Analog

Features : 12-Hour Dial

Indices : Baton Indexes

Lug Width : 11 mm

Max Wrist Size : 5.7 in (14.5 cm)

Model : OMEGA Geneve

Movement : Mechanical (Manual)

Reference Number : 535.025, Cal.635

Style : Classic

Type : Wristwatch

With Manual/Booklet : No

With Original Box/Packaging : No

With Papers : No

Year Manufactured : 1973

Custom Bundle : Yes

Bundle Description : Pouch from Aftermarket Product.

Country of Origin : Switzerland

UPC : Does not apply



Vintage 1973 OMEGA Geneve 535.025 Cal.635 Women's Manual Watch 21mm #k-2008

Description

Overall Condition:

Near MINT

The bracelet is not original.

Serial Number:

36075509

Appearance:

The overall appearance is beautiful.

It has tiny scuffs from normal use.

Please check the photos for details.

Functionality:

It works properly.

Bundled Items:

Pouch from Aftermarket Product.

The package includes exactly the items shown in the photos.

The condition above is based on our own assessment.

Please check the photos carefully and feel free to contact us if you have any questions. Thank you.

Condition grade scale (cosmetic, our own standard, from highest to lowest): Unused > Almost Unused > Top MINT > MINT > Almost MINT > Near MINT > Excellent+++++ > Excellent++++ > Excellent+++ > Excellent. "Excellent" indicates visible signs of use. As-Is and For Parts refer to the operating condition, not the cosmetic grade.

Please Note (Vintage Watch):

This is a vintage watch.

Water resistance is not guaranteed on vintage watches, so please keep the watch away from water.

Vintage mechanical watches may run slightly fast or slow compared to modern watches; this is normal for their age.

For quartz watches, the battery is a consumable and may need replacement in the future.

Photos are screen grabs from Chrono24

Thanks!

The watch is authentic. Obviously the bracelet is an aftermarket piece.
For me the price is too high, especially with the watch running +35s/d. And you only have the reading in one position (dial up).
If it has to be this model exactly and time pressure, maybe you do not have a choice.. But I bought watches like that in good condition for around 60-120€ in the past when they were up for auction.