Princess 300 with RaRo Elite Imperial typeface
The "AR" foundry mark is a shorthand for Albert Rodrian, one half of RaRo. If you ever see an R inside an octagon that's the mark for the other half, Alfred Ransmayer.
The "84" on the foundry mark is typical of RaRo's 12 pitch Elite Imperial which can be found with a sample at: https://typecast.munk.org/2023/02/04/1961-adler-typewriter-type-font-styles/
You can also compare other known Princess typefaces at the database: https://typewriterdatabase.com/twdb.0.typefaces?mfr_search=70&model_search=100#
If you put a ruler up to your type, you should find that there are 12 characters per inch.
You can also cross reference the following: - the Hass catalog, page 3, row 1:<br /> https://archive.org/details/typewriter-foundry-marks-haas/page/n1/mode/2up<br /> - RaRo Catalogue Page B3-4 "Elite-Schatten Ro 84":<br /> https://www.sommeregger.name/typewriters/files/RaRo/rarotype_katalog_1980_OCR_20160523.pdf
Reply to u/CaptainCulinary at https://old.reddit.com/r/typewriters/comments/1wjb0gk/princess_300_with_typeface/