Allied doesn't seem to list any Blessing parts for anything besides trumpets/cornets, trombones, and marching mellophones (and no valve guides for those). They have the following message on their Blessing page:
"The Blessing name is now owned by St. Louis Music and they are importing Blessing instruments from China. Please contact them for parts."
If you want to keep the instrument and use it, it might be possible for a tech to modify some other valve guides for it. Or an alternative might be to remove those valve guides and install old-style screw-in guides (I'd suggest nylon) in the pistons. That's not hard to do (drill, tap, screw in nylon screw, form the head appropriately).
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)