Solved: PN #924 -- Sétabusz (Tourist Bus) by Budapesti Jármű KTSZ, 1967

[pnegyesi]

Kölcsönző means rental, so no
(Bérgép means a machine for rent)

[pguillem]

Trying combinations of Hungarian words, but with no success.  Is it an ad bus ?

[pnegyesi]

no

[pguillem]

A mobile workshop ?

[pnegyesi]

no

[oko94]

Kecskeméti Mezőgép Vállalat ?

[pnegyesi]

now we are talking But no, not them

[oko94]

Can the puzzle photo be found on a Facebook page ?

[pnegyesi]

the puzzle picture is not featured on Facebook, but you can find some info on another similar bus by the same company

[pguillem]

Budapest BNV ?

[pnegyesi]

that was an industrial fair, so no

[pguillem]

OMÉK-on ?

[pnegyesi]

OMÉK is an agricultural fair, so no

[pguillem]

Dutra ?

[pnegyesi]

no, that was a tractor company

[oko94]

Designed by József Cserny for Budapesti Jármű KTSZ ?

[pnegyesi]

Really, really, really well-done!!! Sorry pguillem

This was a bus which carried tourists in the Bakony hills

[oko94]

Well, I just had to click twice to find the hint on a Facebook page, so it wasn't that hard after all 

Thanks for my 575th point !

[pguillem]

No Sétabusz at the Magyar Műszaki és Közlekedési Múzeum Facebook page, only a Hegyi Busz. I just found your second image at index.hu, with no explanations at all...

[pnegyesi]

Yes, the Hegyi Busz was made by the same company, designed by the same designer

[pnegyesi]

Some original photos from the archives of the Hungarian Museum of Transport.