Ritzmar upright Piano

[sean]

Trying to establish value of Upright piano stamped Ritzmar and manufactured by ewing and McIntosh of Glasgow

[Bill Kibby]

I don't think you will find that it was manufactured by Ewing & M'Intosh. They were retailers. Ritzmar does not seem to be a real maker's name, and my Names page at pianohistory.info explains that many piano names are meaningless.
Nobody anywhere can guess the value or condition of a piano without inspecting it on the spot, and checking how well it holds in tune, so your local tuner is the best person to ask.