Apparently the "DRPa" marked on this rifle is the equivalent of "patent pending", making it a transitional model. Note that this rifle is missing the original trigger adjustment locking screw, and the rear sight is not original. With thanks to Mike D for the pics.
This was the second incarnation of the model 35, first introduced around 1936 in both .177 and .22 calibres and having a walnut half stock and the independent cocking double-pull trigger.
In his articles for Guns Review on the Mayer and Grammelspacher story, airgun writer John Walter said of this model: "It was a very popular gun and a big seller [after the War]. The version made between 1936 and 1939 was only made in small numbers before war curtailed sales outside Germany; thus, it is rare and much sought after by collectors of M&G guns."
This is an interesting rifle. A 1930s Diana 35 with the final pre-WW2 pattern double pull trigger. It also has the later type stock, common to the DRP and DRPa model 35s. But it has the metal buttplate of the previous model 35, which strongly suggests it is a very early transitional model.
It also lacks any markings at all, apart from the Diana mod. 35 stamp and the Diana goddess on the top of the cylinder. There is neither a date stamp, which is often seen on the first pattern mod 35, or a DRP or DRPa stamp on the rear left side of the cylinder.
Interestingly, it did have "Made in Germany" stamped just below the Diana Mod. 35 on the cylinder but someone has gouged a deep groove across this mark with a file to obliterate it. You can just make out the letter "M" at the beginning and the tops of the rest of the letters.
This gun was found in the United Kingdom so it seems likely a former owner mutilated it to disguise its origins, probably in the late 1930s, '40s or '50s when anti-German feeling was strongest. The finish on the groove matches the patina of the rest of the top of the cylinder, so it was clearly done many years ago.
With thanks to Steve in the US for pics of this superb example in .22 cal, made around the early 1930s. Much of the original blueing remains. The stock is a reproduction based on an original by stock-maker Jim Maccari. The front sight is a replacement made by Lyman. Steve says there are no markings other than a "437" stamped on the lug below the trigger block.
With many thanks to Dan in the US for these pics. It has no model identification. It also has the early pattern "BSA-style" front sight and a later pattern Diana goddess stamp (ie. not showing so much leg). Probably made in the early 1930s.