I have seen the P-H converted to .22 BSR's at gunshows over the years. The conversions seem nicely done but the sellers have always been asking close to what you could buy a slightly used Model 17 for. I would buy one if it were under $300 and in excellent shape.
The .38's are ones that I would stay away from.
Plus 1 generally to my fellow Oblast resident!

I can't really speak to Parker Hale conversions. But personal experience, fifties & sixties, very many gun conversions. Bolt rifles surviving well. Such as revolvers... Generally 'other'! Bought a Winfield Arms Victory model conversion to .38 Spl. From them in La @ $2995. Reblued & "genuine" plastic staghorn grips" Wooee! Cases regularly stuck & as extracted, slight "bottleneck", likely requiring chambers polished, never accomplished. Thepoint, a lot of firms buying in quantity,converting w/minimalist work to get them out the door. 38 S&W definitely not 'sexy' by the fifites and most of these conversion themselves not so by the sixties.
I have a Colt "Official Police", .22, c. 1948, paid about $50 in that latter era with ammo supply. Way nice quality "working type" gun! Quite decent, pix below.
The comparison.... Golden State Arms did a ton of rifles, but for most part, doing conversions right. Farming large numbers such as P17 Enfields out, not to "gunsmiths". Rather to machine & woodworking shops. Production style alterations. What they did, they did right. To my (inexpert) knowledge, not many in 'refurb' industry with such operation.
The net here, nothing against Parker Hale, just really cautions about handgun "conversions". As the comment here, not that competitive against the 'real deal' Smiths & Colts.
A long winded...
My take!
John