1921-22 W575-1 Walter Johnson

[oldeboo]

It indeed appears to be a W575-1. Here is a pretty good write up if you're interested in learning about the W575-1 cards(and others):

https://prewarcards.com/2016/10/05/1...trip-card-set/

W575-1 cards are similar to the E121 series and a few others. The main difference being the W575-1 are considered a strip card with a blank back. Here is some info on the E121 cards for comparison:

https://prewarcards.com/2016/10/03/1...n-caramel-set/

Here are a couple more links to dig around from the grading companies that show population reports and such:
https://www.psacard.com/cardfacts/ba...22-w575-1/6113
https://gosgc.com/pop-report/result/...575-1/Baseball

Handwriting on a card typically makes a card less desirable, but also more affordable. In some cases with rare cards it's hard to be overly fussy. For many, any Walter Johnson card is a good Walter Johnson card. As far as determining a fair price, that's up to you as a buyer. Maybe others will chime in on that.