Your Radio Delicia (Delicia Radio) was made by the Ligna harmonica company of Czechoslovakia, production dates unknown, but you’ve written that it’s a 1989 vintage. It has metal covers that wrap around the edges of the harmonica.
It’s a 12-double holes, 24 reeds tremolo harmonica. It’s most common in the key of C. Tremolo harmonicas have a single reed in each chamber. They are paired vertically with the same pitched reed, but it’s slightly de-tuned at the factory. When the two vertically-paired reeds are played together, an automatic wavy tone(tremolo) is heard.
It may be a copy of the Hohner Chimes harmonica, made from circa 1924-'36.
If it’s key is C (usually found stamped on the top cover), it usually has the E vertically-paired reeds as it’s lowest pitched reed (first hole on the left). It has a complete major scale from holes 5-12.
On the following chart, large letters are exhale reeds and small letters are inhale reeds:
Ligna Delicia Radio, key of C major, starting on “mi” of the scale:
||E|g|G|b|C|d|E|f|G|a|C|b|| (this is the top reed plate. The bottom plate is identical to the top plate)
The Harmonic Reed company’s Roy Rogers Riders harmonica is a 10-hole Richter system diatonic harmonica,
made circa 1950-'72. 1939 was the Harmonic Reed’s first year, and 1972 was it’s last year in business. It was located in Philadelphia, Pennsylvania, USA, until it’s later years, when the company was sold and moved to Conshohoken, Pennsylvania.
Richter system harmonicas were invented by Joseph Richter in 1858 Haidau (today’s Novy Bohr), Czechoslovakia, after he saw the reed placement in an accordion factory. On a Richter single reed per note harmonica, the top reed plate has exhale reeds and the bottom reed plate has inhale reeds. This is to permit chordal playing, and self-accompaniment chords & melody.
Harmonic Reed Co. Roy Rogers Riders 10-hole single -reed per note diatonic harp, key of C only:
||C d |E g |G b |C d |E f |G a |b C |d E |f G |a C||
The Roy Rogers Riders harp had metal covers. The rest was plastic, including the reed plates and even the reeds.
It’s a weak-sounding harp, with air leakage, and would not be recommended for serious playing.
As The Bugle Boy recommended, try a more expensive diatonic single reed blues harp-type harmonica, in the $25-$40 range, if you are serious about playing the harmonica.