If it helps, you can view your transaction history at
user.frontierstore.net
It allows you to see your purchase history in "
My Orders" (under "User"), and - weirdly
only showing up in the menu if I load it on a mobile device - also all your history of in-game acquisitions such as paintjobs and ship kits in "
My Entitlements", a necessary distinction since these days your purchases are now for Arx top-ups, so to see what you actually acquired with the Arx you use the "My Entitlements" list. (The Entitlements list also shows all the stuff you acquired non-monetarily; promotions, community goal prizes, etc.)
There is another menu option "Steam Entitlements"; this is separate from "My Entitlements", and does show up on desktop. My account is direct with FDev (so that FDev doesn't have to pay Valve/Steam a whopping 30% of every micro-transaction), so my Steam Entitlements is empty, but is presumably different if you purchased the game from Valve.
[browsing down memory lane in my own history - oh wow; I have a flag paint for the Cobra too. I thought I only had it for the Viper]