The Loco Add-On Bundle is available from the Windows Store, but I'm not seeing it available from Steam or Epic.
On Steam I can see the 3 individual packs @ £4.99, but not the £11.99 for all 3 option. On Epic, neither the singles or the bundle are visible for me.
I can see the bundle in steam. You need to click into one of individual items first and then there is the bundle option.
Still not seeing any of the "loco add-on" content for sale on Epic, either through the client or web site.